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Interview questions n answers

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Interview questions and answers of computer network.

Interview questions and answers of computer network.

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  • 1. 1 Q: - What’s the difference between local, global and universal groups? Domain local groups assign access permissions to global domain groups for local domain resources. Global groups provide access to resources in other trusted domains. Universal groups grant access to resources in all trusted domains. Q: -I am trying to create a new universal user group. Why can’t I? Universal groups are allowed only in native-mode Windows Server 2003 environments. Native mode requires that all domain controllers be promoted to Windows Server 2003 Active Directory. Q: -What is LSDOU? It’s group policy inheritance model, where the policies are applied to Local machines, Sites, Domains and Organizational Units. Q: - Why doesn’t LSDOU work under Windows NT? If the NTConfig.pol file exists, it has the highest priority among the numerous policies. Q: -Where are group policies stored? %SystemRoot%System32GroupPolicy Q: -What is GPT and GPC? Group policy template and group policy container. Q: - Where is GPT stored? %SystemRoot%SYSVOLsysvoldomainnamePoliciesGUID Q: - You change the group policies, and now the computer and user settings are in conflict. Which one has the highest priority? The computer settings take priority. Q: -You want to set up remote installation procedure, but do not want the user to gain access over it. What do you do? gponame–> User Configuration–> Windows Settings–> Remote Installation Services–> Choice Options is your friend. Q: - 10. What’s contained in administrative template conf.adm? Microsoft NetMeeting policies Q: -How can you restrict running certain applications on a machine? Via group policy, security settings for the group, then Software Restriction Policies. Q: -You need to automatically install an app, but MSI file is not available. What do you do? A .zap text file can be used to add applications using the Software Installer, rather than the Windows Installer.
  • 2. 2 Q: - What’s the difference between Software Installer and Windows Installer? The former has fewer privileges and will probably require user intervention. Plus, it uses .zap files. Q: -What can be restricted on Windows Server 2003 that wasn’t there in previous products? Group Policy in Windows Server 2003 determines a users right to modify network and dial-up TCP/IP properties. Users may be selectively restricted from modifying their IP address and other network configuration parameters. Q: -How frequently is the client policy refreshed? 90 minutes give or take. Q: - Where is secedit? It’s now gpupdate. Q: -You want to create a new group policy but do not wish to inherit. Make sure you check Block inheritance among the options when creating the policy. Q: -What is "tattooing" the Registry? The user can view and modify user preferences that are not stored in maintained portions of the Registry. If the group policy is removed or changed, the user preference will persist in the Registry. Q: - How do you fight tattooing in NT/2000 installations? You can’t. Q: -How do you fight tattooing in 2003 installations? User Configuration - Administrative Templates - System - Group Policy - enable - Enforce Show Policies Only. Q: -What does IntelliMirror do? It helps to reconcile desktop settings, applications, and stored files for users, particularly those who move between workstations or those who must periodically work offline. Q: - What’s the major difference between FAT and NTFS on a local machine? FAT and FAT32 provide no security over locally logged-on users. Only native NTFS provides extensive permission control on both remote and local files. Q: - How do FAT and NTFS differ in approach to user shares? They don’t, both have support for sharing. Q: -Explan the List Folder Contents permission on the folder in NTFS. Same as Read & Execute, but not inherited by files within a folder. However, newly created subfolders will inherit this permission.
  • 3. 3 Q: - I have a file to which the user has access, but he has no folder permission to read it. Can he access it? It is possible for a user to navigate to a file for which he does not have folder permission. This involves simply knowing the path of the file object. Even if the user can’t drill down the file/folder tree using My Computer, he can still gain access to the file using the Universal Naming Convention (UNC). The best way to start would be to type the full path of a file into Run… window. Q: - For a user in several groups, are Allow permissions restrictive or permissive? Permissive, if at least one group has Allow permission for the file/folder, user will have the same permission. Q: -For a user in several groups, are Deny permissions restrictive or permissive? Restrictive, if at least one group has Deny permission for the file/folder, user will be denied access, regardless of other group permissions. Q: - What hidden shares exist on Windows Server 2003 installation? Admin$, Drive$, IPC$, NETLOGON, print$ and SYSVOL. Q: - What’s the difference between standalone and fault-tolerant DFS (Distributed File System) installations? The standalone server stores the Dfs directory tree structure or topology locally. Thus, if a shared folder is inaccessible or if the Dfs root server is down, users are left with no link to the shared resources. A fault-tolerant root node stores the Dfs topology in the Active Directory, which is replicated to other domain controllers. Thus, redundant root nodes may include multiple connections to the same data residing in different shared folders. Q: -We’re using the DFS fault-tolerant installation, but cannot access it from a Win98 box. Use the UNC path, not client, only 2000 and 2003 clients can access Server 2003 fault-tolerant shares. Q: - Where exactly do fault-tolerant DFS shares store information in Active Directory? In Partition Knowledge Table, which is then replicated to other domain controllers. Q: -Can you use Start->Search with DFS shares? Yes. Q: -What problems can you have with DFS installed? Two users opening the redundant copies of the file at the same time, with no file-locking involved in DFS, changing the contents and then saving. Only one file will be propagated through DFS. Q: - I run Microsoft Cluster Server and cannot install fault-tolerant DFS. Yeah, you can’t. Install a standalone one. Q: -Is Kerberos encryption symmetric or asymmetric? Symmetric.
  • 4. 4 Q: -How does Windows 2003 Server try to prevent a middle-man attack on encrypted line? Time stamp is attached to the initial client request, encrypted with the shared key. Q: - What hashing algorithms are used in Windows 2003 Server? RSA Data Security’s Message Digest 5 (MD5), produces a 128-bit hash, and the Secure Hash Algorithm 1 (SHA-1), produces a 160-bit hash. Q: - What third-party certificate exchange protocols are used by Windows 2003 Server? Windows Server 2003 uses the industry standard PKCS-10 certificate request and PKCS-7 certificate response to exchange CA certificates with third-party certificate authorities. Q: -What’s the number of permitted unsuccessful logons on Administrator account? Unlimited. Remember, though, that it’s the Administrator account, not any account that’s part of the Administrators group. Q: - If hashing is one-way function and Windows Server uses hashing for storing passwords, how is it possible to attack the password lists, specifically the ones using NTLMv1? A cracker would launch a dictionary attack by hashing every imaginable term used for password and then compare the hashes. Q: -What’s the difference between guest accounts in Server 2003 and other editions? More restrictive in Windows Server 2003. Q: -How many passwords by default are remembered when you check "Enforce Password History Remembered"? User’s last 6 passwords. Q: - What is DHCP? DHCP stands for "Dynamic Host Configuration Protocol". Q: - What is DHCP's purpose? DHCP's purpose is to enable individual computers on an IP network to extract their configurations from a server (the 'DHCP server') or servers, in particular, servers that have no exact information about the individual computers until they request the information. The overall purpose of this is to reduce the work necessary to administer a large IP network. The most significant piece of information distributed in this manner is the IP address. Q: - Can DHCP work with Apple Talk or IPX? No, it is too tied to IP. Furthermore, they don't need it since they have always had automated mechanisms for assigning their own network addresses.
  • 5. 5 Q: - What is a DHCP lease? A DHCP lease is the amount of time that the DHCP server grants to the DHCP client permission to use a particular IP address. A typical server allows its administrator to set the lease time. Q: - What is a Client ID? What is termed the Client ID for the purposes of the DHCP protocol is whatever is used by the protocol to identify the client computer. By default, DHCP implementations typically employ the client's MAC address for this purpose, but the DHCP protocol allows other options. Some DHCP implementations have a setup option to specify the client ID you want. One alternative to the MAC address is simply a character string of your choice. In any case, in order for DHCP to function, you must be certain that no other client is using the client ID you choose, and you must be sure the DHCP server will accept it. Q: - Can DHCP support statically defined addresses?? Yes. At least there is nothing in the protocol to preclude this and one expects it to be a feature of any DHCP server. This is really a server matter and the client should work either way. The RFC refers to this as manual allocation. Q: - What is a MAC address? A MAC address (also called an Ethernet address or an IEEE MAC address) is a number (typically written as twelve hexadecimal digits, 0 through 9 and A through F, or as six hexadecimal numbers separated by periods or colons, i.e. 0080002012ef, 0:80:0:2:20:ef) which uniquely identifes a computer that has an Ethernet interface. Unlike the IP number, it includes no indication of where your computer is located. In DHCP's typical use, the server uses a requesting computer's MAC address to uniquely identify it. Q: - What protocol and port does DHCP use? DHCP, like BOOTP runs over UDP, utilizing ports 67 and 68. Q: - What is an IP address? An IP address (also called an IP number) is a number (typically written as four numbers separated by periods, i.e. 107.4.1.3 or 84.2.1.111) which uniquely identifies a computer that is making use of the Internet. It is analogous to your telephone number in that the telephone number is used by the telephone network to direct calls to you. The IP address is used by the Internet to direct data to your computer, e.g. the data your web browser retrieves and displays when you surf the net. One task of DHCP is to assist in the problem of getting a functional and unique IP number into the hands of the computers that make use of the Internet. Q: - Who Created It? How Was It Created? DHCP was created by the Dynamic Host Configuration Working Group of the Internet Engineering Task Force (IETF; a volunteer organization which defines protocols for use on the Internet). As such, it's definition is recorded in an Internet RFC and the Internet Activities Board (IAB) is asserting its status as to Internet Standardization. As of this writing (June 1998), DHCP is an Internet Draft Standard Protocol and is Elective. BOOTP is an Internet Draft Standard Protocol and is recommended. For more information on Internet standardization, see RFC2300 (May 1998)
  • 6. 6 Q: - How is it different than BOOTP or RARP? DHCP is based on BOOTP and maintains some backward compatibility. The main difference is that BOOTP was designed for manual pre-configuration of the host information in a server database, while DHCP allows for dynamic allocation of network addresses and configurations to newly attached hosts. Additionally, DHCP allows for recovery and reallocation of network addresses through a leasing mechanism. RARP is a protocol used by Sun and other vendors that allows a computer to find out its own IP number, which is one of the protocol parameters typically passed to the client system by DHCP or BOOTP. RARP doesn't support other parameters and using it, a server can only serve a single LAN. DHCP and BOOTP are designed so they can be routed. Q: - How does DHCP and BOOTP handle multiple subnets? For the situations where there is more than one LAN, each with its own subnet number, there are two ways. First of all, you can set up a seperate server on each subnet. Secondly, a feature of some routers known as "BOOTP forwarding" to forward DHCP or BOOTP requests to a server on another subnet and to forward the replies back to the client. The part of such a router (or server acting as a router) that does this is called a "BOOTP forwarding agent". Typically you have to enable it on the interface to the subnet to be served and have to configure it with the IP address of the DHCP or BOOTP server. On a Cisco router, the address is known as the "UDP Helper Address". Q: - Can a BOOTP client boot from a DHCP server? Only if the DHCP server is specifically written to also handle BOOTP queries. Q: - Can a DHCP client boot from a BOOTP server? Only if the DHCP client were specifically written to make use of the answer from a BOOTP server. It would presumably treat a BOOTP reply as an unending lease on the IP address. In particular, the TCP/IP stack included with Windows 95 does not have this capability. Q: - Is a DHCP server "supposed to" be able to support a BOOTP client? The RFC on such interoperability (1534) is clear: "In summary, a DHCP server: ... MAY support BOOTP clients," (section 2). The word "MAY" indicates such support, however useful, is left as an option. A source of confusion on this point is the following statement in section 1.5 of RFC 1541: "DHCP must provide service to existing BOOTP clients." However, this statement is one in a list of "general design goals for DHCP", i.e. what the designers of the DHCP protocol set as their own goals. It is not in a list of requirements for DHCP servers. Q: - Can a DHCP server back up another DHCP server? You can have two or more servers handing out leases for different addresses. If each has a dynamic pool accessible to the same clients, then even if one server is down, one of those clients can lease an address from the other server. However, without communication between the two servers to share their information on current leases, when one server is down, any client with a lease from it will not be able to renew their lease with the other server. Such communication is the purpose of the "server to server protocol" (see next question). It is possible that some server vendors have addressed this issue with their own proprietary server-to-server communication.
  • 7. 7 Q: - When will the server to server protocol be defined? The DHC WG of the IETF is actively investigating the issues in inter-server communication. The protocol should be defined "soon". Q: - What is DHCP Spoofing? Ascend Pipeline ISDN routers (which attach Ethernets to ISDN lines) incorporate a feature that Ascend calls "DHCP spoofing" which is essentially a tiny server implementation that hands an IP address to a connecting Windows 95 computer, with the intention of giving it an IP number during its connection process. Q: - How long should a lease be? A very relevant factor is that the client starts trying to renew the lease when it is halfway through: thus, for example, with a 4 day lease, the client which has lost access to its DHCP server has 2 days from when it first tries to renew the lease until the lease expires and the client must stop using the network. During a 2- day outage, new users cannot get new leases, but no lease will expire for any computer turned on at the time that the outage commences. Another factor is that the longer the lease the longer time it takes for client configuration changes controlled by DHCP to propogate. Q: - How can I prevent unauthorized laptops from using a network that uses DHCP for dynamic addressing? This would have to be done using a mechanism other than DHCP. DHCP does not prevent other clients from using the addresses it is set to hand out nor can it distinguish between a computer's permanent MAC address and one set by the computer's user. DHCP can impose no restrictions on what IP address can use a particular port nor control the IP address used by any client. Q: - What is a DHCP lease? A DHCP lease is the amount of time that the DHCP server grants to the DHCP client permission to use a particular IP address. A typical server allows its administrator to set the lease time. Q: - What is a Client ID? What is termed the Client ID for the purposes of the DHCP protocol is whatever is used by the protocol to identify the client computer. By default, DHCP implementations typically employ the client's MAC address for this purpose, but the DHCP protocol allows other options. Some DHCP implementations have a setup option to specify the client ID you want. One alternative to the MAC address is simply a character string of your choice. In any case, in order for DHCP to function, you must be certain that no other client is using the client ID you choose, and you must be sure the DHCP server will accept it. Q: - Can DHCP support statically defined addresses? Yes. At least there is nothing in the protocol to preclude this and one expects it to be a feature of any DHCP server. This is really a server matter and the client should work either way. The RFC refers to this as manual allocation. Q: - How is it different than BOOTP or RARP? DHCP is based on BOOTP and maintains some backward compatibility. The main difference is that BOOTP was designed for manual pre-configuration of the host information in a server database, while DHCP allows for dynamic allocation of network addresses and configurations to newly attached hosts. Additionally, DHCP allows for recovery and reallocation of network addresses through a leasing mechanism.
  • 8. 8 RARP is a protocol used by Sun and other vendors that allows a computer to find out its own IP number, which is one of the protocol parameters typically passed to the client system by DHCP or BOOTP. RARP doesn't support other parameters and using it, a server can only serve a single LAN. DHCP and BOOTP are designed so they can be routed. Q: - What is an IP address? An IP address (also called an IP number) is a number (typically written as four numbers separated by periods, i.e. 107.4.1.3 or 84.2.1.111) which uniquely identifies a computer that is making use of the Internet. It is analogous to your telephone number in that the telephone number is used by the telephone network to direct calls to you. The IP address is used by the Internet to direct data to your computer, e.g. the data your web browser retrieves and displays when you surf the net. One task of DHCP is to assist in the problem of getting a functional and unique IP number into the hands of the computers that make use of the Internet. Q: - What is a MAC address? A MAC address (also called an Ethernet address or an IEEE MAC address) is a number (typically written as twelve hexadecimal digits, 0 through 9 and A through F, or as six hexadecimal numbers separated by periods or colons, i.e. 0080002012ef, 0:80:0:2:20:ef) which uniquely identifes a computer that has an Ethernet interface. Unlike the IP number, it includes no indication of where your computer is located. In DHCP's typical use, the server uses a requesting computer's MAC address to uniquely identify it. Q: - Can DHCP work with AppleTalk or IPX? No, it is too tied to IP. Furthermore, they don't need it since they have always had automated mechanisms for assigning their own network addresses. Q: - What is DHCP's purpose? DHCP's purpose is to enable individual computers on an IP network to extract their configurations from a server (the 'DHCP server') or servers, in particular, servers that have no exact information about the individual computers until they request the information. The overall purpose of this is to reduce the work necessary to administer a large IP network. The most significant piece of information distributed in this manner is the IP address. Q: - How does DHCP and BOOTP handle multiple subnets? For the situations where there is more than one LAN, each with its own subnet number, there are two ways. First of all, you can set up a seperate server on each subnet. Secondly, a feature of some routers known as "BOOTP forwarding" to forward DHCP or BOOTP requests to a server on another subnet and to forward the replies back to the client. The part of such a router (or server acting as a router) that does this is called a "BOOTP forwarding agent". Typically you have to enable it on the interface to the subnet to be served and have to configure it with the IP address of the DHCP or BOOTP server. On a Cisco router, the address is known as the "UDP Helper Address". Q: - Can a DHCP client boot from a BOOTP server? Only if the DHCP client were specifically written to make use of the answer from a BOOTP server. It would presumably treat a BOOTP reply as an unending lease on the IP address. In particular, the TCP/IP stack included with Windows 95 does not have this capability.
  • 9. 9 Q: - Is a DHCP server "supposed to" be able to support a BOOTP client? The RFC on such interoperability (1534) is clear: "In summary, a DHCP server: ... MAY support BOOTP clients," (section 2). The word "MAY" indicates such support, however useful, is left as an option. A source of confusion on this point is the following statement in section 1.5 of RFC 1541: "DHCP must provide service to existing BOOTP clients." However, this statement is one in a list of "general design goals for DHCP", i.e. what the designers of the DHCP protocol set as their own goals. It is not in a list of requirements for DHCP servers. Q: - Is a DHCP client "supposed to" be able to use a BOOTP server? The RFC on such interoperability (1534) is clear: "A DHCP client MAY use a reply from a BOOTP server if the configuration returned from the BOOTP server is acceptable to the DHCP client." (section 3). The word "MAY" indicates such support, however useful, is left as an option. Q: - Can a DHCP server back up another DHCP server? You can have two or more servers handing out leases for different addresses. If each has a dynamic pool accessible to the same clients, then even if one server is down, one of those clients can lease an address from the other server. However, without communication between the two servers to share their information on current leases, when one server is down, any client with a lease from it will not be able to renew their lease with the other server. Such communication is the purpose of the "server to server protocol" (see next question). It is possible that some server vendors have addressed this issue with their own proprietary server-to-server communication. Q: - When will the server to server protocol be defined? The DHC WG of the IETF is actively investigating the issues in inter-server communication. The protocol should be defined "soon". Q: - How can I relay DHCP if my router does not support it? A server on a net(subnet) can relay DHCP or BOOTP for that net. Microsoft has software to make Windows NT do this. Q: - What is DHCP Spoofing? Ascend Pipeline ISDN routers (which attach Ethernets to ISDN lines) incorporate a feature that Ascend calls "DHCP spoofing" which is essentially a tiny server implementation that hands an IP address to a connecting Windows 95 computer, with the intention of giving it an IP number during its connection process. Q: - How long should a lease be? A very relevant factor is that the client starts trying to renew the lease when it is halfway through: thus, for example, with a 4 day lease, the client which has lost access to its DHCP server has 2 days from when it first tries to renew the lease until the lease expires and the client must stop using the network. During a 2- day outage, new users cannot get new leases, but no lease will expire for any computer turned on at the time that the outage commences. Another factor is that the longer the lease the longer time it takes for client configuration changes controlled by DHCP to propogate. Q: - How can I prevent unauthorized laptops from using a network that uses DHCP for dynamic addressing? This would have to be done using a mechanism other than DHCP. DHCP does not prevent other clients from using the addresses it is set to hand out nor can it distinguish between a computer's permanent MAC address and one set by the
  • 10. 10 computer's user. DHCP can impose no restrictions on what IP address can use a particular port nor control the IP address used by any client. Q: - Can a BOOTP client boot from a DHCP server? Only if the DHCP server is specifically written to also handle BOOTP queries. Q: - Can DHCP support remote access? PPP has its own non-DHCP way in which communications servers can hand clients an IP address called IPCP (IP Control Protocol) but doesn't have the same flexibility as DHCP or BOOTP in handing out other parameters. Such a communications server may support the use of DHCP to acquire the IP addresses it gives out. This is sometimes called doing DHCP by proxy for the client. I know that Windows NT's remote access support does this. A feature of DHCP under development (DHCPinform) is a method by which a DHCP server can supply parameters to a client that already has an IP number. With this, a PPP client could get its IP number using IPCP, then get the rest of its parameters using this feature of DHCP. SLIP has no standard way in which a server can hand a client an IP address, but many communications servers support non- standard ways of doing this that can be utilized by scripts, etc. Thus, like communications servers supporting PPP, such communications servers could also support the use of DHCP to acquire the IP addresses to give out. The DHCP protocol is capable of allocating an IP address to a device without an IEEE-style MAC address, such as a computer attached through SLIP or PPP, but to do so, it makes use of a feature which may or may not be supported by the DHCP server: the ability of the server to use something other than the MAC address to identify the client. Communications servers that acquire IP numbers for their clients via DHCP run into the same roadblock in that they have just one MAC address, but need to acquire more than one IP address. One way such a communications server can get around this problem is through the use of a set of unique pseudo-MAC addresses for the purposes of its communications with the DHCP server. Another way (used by Shiva) is to use a different "client ID type" for your hardware address. Client ID type 1 means you're using MAC addresses. However, client ID type 0 means an ASCII string. Q: - Explain the functionality of PING. Ping Is particularly used to check if the system is in network or not. It also gives packet lost information. In windows ping command is written as ping ip_address. The output returns the data packets information. The number of packets sent, received and lost is returned by PING. Q: - What is multicasting? Multicasting allows a single message to be sent to a group of recipients. Emailing, teleconferencing, are examples of multicasting. It uses the network infrastructure and standards to send message. Q: - What is Telnet ? Telnet is the main Internet protocol for creating a connection to a remote server. Q: - Explain token ring technology. In this technology, all the devices are arranged in a circle. A token moves around the circular network. A device waits for the token before it sends its frame. Once it receives token, it initiates transmission of its frame.
  • 11. 11 Q: - What is NetBIOS protocol? NetBIOS (Network Basic Input/Output System) Protocol allows applications on separate computers to communicate over a LAN. It runs over TCP/IP giving each computer in the network a NetBIOS name and IP address. E.g. It can be used for computers running Windows 2000 (or before) to join a computer network running Windows 2000 (or later). Q: - What is TCP / IP protocol? Transmission Control Protocol / Internet Protocol: - It is a family of protocols used for communication and connection between hosts on the internet. It is the most widely used standard for transmitting data over the internet. The four layers in the protocol are (from bottom to top):- Physical layer, Data link layer, Network layer, transport layer and application layer, also called as the OSI model. In TCP/IP , IP is responsible for forwarding packets while TCP ensures the correct delivery of data from client to server. TCP detects loss of data as well. Q: - What is NNTP (Network News Transfer Protocol)? NNTP or Network News Transfer Protocol is used to manage the notes posted on Unset newsgroup (a collection of posted notes on a subject posted by different users). NNTP servers are responsible for managing Usenet newsgroup collected globally. A NTTP client is a part of the web browser also called as a news reader. It uses a reserver port no 119. Q: - What is SNMP (Simple Network Management Protocol)? SNMP or Simple Network Management Protocol is typically used for managing the network. Managing the network includes managing the nodes present in the network. These nodes may be server, routers, bridges and hubs. SNMP agents are used to achieve this. Managing the network is essential because it helps to monitor network performance, detect network faults or failures, audit network usage etc. the SNMP messages like TRAP, GET or SET may be invoked by network elements or network management system. Q: - What is Routing table? A routing table stores the routes of the various nodes in a network. Nodes can be any electronic device connected to the network. The table is usually stored in a router or the network computer as a database or file. This information helps to fond the best possible path. The routing table has at least 3 fields: the destination network id, cost of the path, next hop or address to send the packet. Q: - What Is Active Directory? Active Directory consists of a series of components that constitute both its logical structure and its physical structure. It provides a way for organizations to centrally manage and store their user objects, computer objects, group membership, and define security boundaries in a logical database structure. Q: - What is the Purpose of Active Directory? Active Directory stores information about users, computers, and network resources and makes the resources accessible to users and applications. It provides a consistent way to name, describe, locate, access, manage, and secure information about these resources.
  • 12. 12 Q: - What are the Functions of Active Directory? Active Directory provides the following functions: Centralizes control of network resources By centralizing control of resources such as servers, shared files, and printers, only authorized users can access resources in Active Directory. Centralizes and decentralizes resource management Administrators have Centralized Administration with the ability to delegate administration of subsets of the network to a limited number of individuals giving them greater granularity in resource management. Store objects securely in a logical structure Active Directory stores all of the resources as objects in a secure, hierarchical logical Structure. Optimizes network traffic The physical structure of Active Directory enables you to use network bandwidth more efficiently. For example, it ensures that, when users log on to the network, the authentication authority that is nearest to the user, authenticates them reducing theamount of network traffic. Q: - What Are Objects? An object is a distinct set of attributes that represents a network resource (a user, a computer, a group policy, etc), and object attributes are characteristics of that object stored in the directory. For example, some of the attributes of a user object might include the user’s first name, last name, department, and e-mail address in addition to others. Q: -What Are Organizational Units? An organizational unit (OU) is a versatile container object used to organize objects within a domain into logical administrative groups. These logical administrative groups can include just one type of object or multiple types depending on how an administrator wants to structure it. Think of an OU like a large box that can contain many things, including other boxes (other OUs called sub-OUs), and those boxes can then contain additional boxes (additional sub-OUs) as well. Q: - What Are Domains? The Domain is the core unit of logical structure in Active Directory. Grouping objects into one Or more domains allow a company’s organization to be reflected in its network. All network objects exist within a domain, and each domain stores information only about the Objects it contains (objects that belong to that domain). Q: - What Are Trees? A tree is a grouping or hierarchical arrangement of one or more Windows 2000 / 2003 domains that allows global resource sharing. A tree may consist of a single Windows 2000 domain or multiple domains in a contiguous namespace. You can create a larger tree (contiguous namespace) by joining multiple domains in a hierarchical structure, since all domains within a single tree share a common namespace and a hierarchical naming structure. Following naming conventions, the domain name of a child domain is the name of that child domain appended with the name of the parent domain. Q: - What Are Forests? A forest is a grouping of one or more trees. As noted above with our example of tailspintoys.com and nwtraders.com, each of those is a tree within our forest even though their naming conventions are not related. It does not matter if each Tree is made up with a single, or multiple domains. Forests allow organizations to group together divisions that do not use the same naming scheme, and may need to operate independently, but still need to communicate with the entire organization via transitive trusts, and share the same schema and configuration container. The first domain in the forest is called the forest root domain. The name of that domain refers to the forest, such as nwtraders.msft. By default, the information in Active Directory is shared only within the forest. This way, the forest is a security boundary for the information that is contained in the instance of Active Directory
  • 13. 13 Q: - How many types of replication in Active Directory? Active Directory Intrasite Replication Intrasite replication in Active Directory takes place between domain controllers within the same site. This makes intrasite replication an uncomplicated process. When changes are made to the replica of Active Directory on one particular domain controller, the domain controller contacts the remainder of the domain controllers within the site. The domain controller checks the information it contains against information hosted by the other domain controllers. To perform this analysis, the domain controller utilizes logical sequence numbers. Intrasite replication utilizes the Remote Procedure Call (RPC) protocol to convey replication data over fast, reliable network connections. With intrasite replication, replication data is not compressed. Active Directory Intersite Replication Intersite replication takes place between sites. Intersite replication can utilize either RPC over IP or SMTP to convey replication data. This type of replication has to be manually configured. Intersite replication occurs between two domain controllers that are called bridgeheads or bridgehead servers. The role of a bridgehead server (BS) is assigned to at least one domain controller in a site. A BS in one site deals with replicating changes with other BSs in different sites. You can configure multiple bridgehead servers in a site. It is only these BSs that replicate data with domain controllers in different domains by performing intersite replication with its BS partners. With intersite replication, packets are compressed to save bandwidth. This places additional CPU load on domain controllers assigned the BS role. BSs should therefore be machines that have enough speed and processors to perform replication. Intersite replication takes place over site links by a polling method which is every 180 minutes by default. Q: - What is the role of Global Catalogue server..? Global Catalog Servers Every domain controller stores the objects for the domain in which it is installed. However, a domain controller designated as a global catalog server stores the objects from all domains in the forest. For each object that is not in the domain for which the global catalog server is authoritative as a domain controller, a limited set of attributes is stored in a partial replica of the domain. Therefore, a global catalog server stores its own full, writable domain replica (all objects and all attributes) plus a partial, read-only replica of every other domain in the forest. The global catalog is built and updated automatically by the Active Directory replication system. The global catalog makes it possible for clients to search Active Directory without having to be referred from server to server until a domain controller that has the domain directory partition storing the requested object is found. By default, Active Directory searches are directed to global catalog servers. The first domain controller in a forest is automatically created as a global catalog server. Thereafter, you can designate other domain controllers to be global catalog servers if they are needed. Q: - where do I put FSMOs? FSMO stands for Flexible Single Master Operations and is pronounced “fiz-mo.” FSMOs are tasks performed by specific domain controllers within a domain or forest. Unlike normal Active Directory (AD) operations, which are performed by all domain controllers in a domain, only one domain controller performs the special FSMO tasks. The FSMO tasks, or roles, are • The schema master is responsible for handling all changes to the AD schema. Only one domain controller in a forest acts as the schema master. If a trust relationship is established between two domain trees (thereby establishing a forest), two schema masters will exist in the forest (one from both domains). One of them will automatically stop acting as schema master. • The domain-naming master is responsible for ensuring the uniqueness of domain names throughout a forest and for adding domains to or removing them from the forest. Only
  • 14. 14 one domain controller in a forest acts as the domain-naming master. • The relative ID (RID) master is responsible for issuing RIDs within a domain. Only one domain controller in a domain acts as the RID master. • The infrastructure master is responsible for updating group-to-user references whenever the members of a group are renamed or changed. Only one domain controller in a domain acts as the infrastructure master. The infrastructure master checks a Global Catalog (GC) server to see when changes have been made. • The primary domain controller (PDC) emulator is responsible for updating any Windows NT backup domain controllers (BDCs) in your domain. The PDC emulator also processes password changes from non-Windows 2000 (Win2K) client computers, just as an NT PDC would do. Only one computer in a domain acts as the PDC emulator. Q: - Is there Graphical editors for LDAP ? Yes, Following are some GUI based tools for LDAP - GQ - Java LDAP Browser/Editor - Softerra LDAP Browser Q: - What can i do if my application doesn't speak to LDAP ? Gateway that translate one directory access protocol into another. Q: - How can i join information contained in different directories ? Distributed, Multivendor directories glued together by referrals and references. Q: - What is "LDIF" ? The LDAP Interchange Format (LDIF) is a standard text file format for storing LDAP configuration information and directory contents. LDIF files are often used to import new data into your directory or make changes to existing data. Q: - Name the object class types ? - Structural Object class - Auxiliary Object class - Abstract object classes Q: - What is the name of main configuration file name for LDAP server ? slapd.conf Q: - What is LDAP ? LDAP stands for Lightweight Directory Access Protocol. In plain and simple terms, its a database whereby it has all the details of all of organizations, individuals, and other resources such as files and devices in a network, whether on the Internet or on corporate intranetand whether or not you know the domain name, IP address, or geographic whereabouts. An LDAP directory can be distributed among many servers on a network, then replicated and synchronized regularly. An LDAP server is also known as a Directory System Agent (DSA). Its a not a relational database. Outlook and other email programs uses LDAP to search for a recipient in an organization.
  • 15. 15 Q: - What is the relationship between LDAP and JNDI? JNDI has classes provided by SUN that will help ur appln interact with and LDAP server. JNDI appln work similarly to JDBC applns once and be free to use 'drivers' from different vendors. SUN provides the "driver" that will help interact with the LDAP server. Sun also provides "drivers" for other naming services (like CORBA). Q: - Why LDAP is called light weight? LDAP (Lightweight Directory Access Protocol) is a protocol for communications between LDAP servers and LDAP clients. LDAP servers store "directories" which are access by LDAP clients. LDAP is called lightweight because it is a smaller and easier protocol which was derived from the X.500 DAP (Directory Access Protocol) defined in the OSI network protocol stack. Q: - what is SLAPD? SLAPD stands for Stand-Alone LDAP.Clients connect to the server over the LDAP protocol, usually using a network-based connection (though SLAPD provides a UNIX socket listener). Q: - Which daemons are required for LDAP server? slapd and slurpd Q: - Tell me the name of three LDAP Client utilities or Applications ldapsearch ldapadd ldapmodify Q: - Define Schemas? Schemas provide definitions of the different object classes and attribute types that OpenLDAP should support. Using these, OpenLDAP can determine what entries it is allowed to store, whether any given entry is valid, and how entries should optimally be stored. Q: - Explain modulepath directive? The modulepath directive provides the full path to the directory where the modules (the compiled libraries) are stored Q: - Explain moduleload directive? The moduleload directive instructs OpenLDAP to load a particular module. Q: - What is HDB? HDB is the new generation storage mechanism for OpenLDAP. Like its predecessor, the BDB backend, HDB uses the Oracle BerkeleyDB database for storage, but HDB stores entries hierarchically, a perfect fit for LDAP's tree structure. The old BDB backend is still supported, and you can use it by specifying bdb instead of hdb in the database directive.
  • 16. 16 Q: - Which utility is used to Encrypt the password? ldappasswd Q: - How you will verify LDAP configuration file? Use "slaptest" utility. slaptest -v -f /etc/ldap/slapd.conf Q: - Which configuration file is required for LDAP clients? ldap.conf Q: - Explain "SIZELIMIT" directive? This directive indicates the upper limits on the number of records returned. Q: - Explain "TIMELIMIT" directive? This directive will give the information about the amount of time the client will wait for the server to respond. Q: - Tell me the name of logical operators which are used in ldap filters. AND (&), OR (|), and NOT (!) Q: - What Does slapadd Do? The slapadd utility reads the slapd.conf file, loads the appropriate backend databases, and then reads LDIF data. Q: - Which web based tool you have used for LDAP? phpLDAPadmin Q: - What is Virtualization ? Virtualization (or virtualisation), in computing, is the creation of a virtual (rather than actual) version of something, such as a hardware platform, operating system, a storage device or network resources. Q: - what are the types of hardware virtualization? Full virtualization: Almost complete simulation of the actual hardware to allow software, which typically consists of a guest operating system, to run unmodified Partial virtualization: Some but not all of the target environment is simulated. Some guest programs, therefore, may need modifications to run in this virtual environment. Paravirtualization: A hardware environment is not simulated; however, the guest programs are executed in their own isolated domains, as if they are running on a separate system. Guest programs need to be specifically modified to run in this environment.
  • 17. 17 Q: - What are the benefits of virtualization? Virtualization is a creation of virtual machines and to manage them from one place. It allows the resources to be shared with large number of network resources. Virtualization is having lots of benefits and they are as follows: 1. It helps in saving lots of cost and allows to easily maintaining it, in less cost. 2. It allows multiple operating systems on one virtualization platform. 3. It removes the dependency of heavy hardware to run the application. 4. It provides consolidating servers that are used for crashing of a server purpose 5. It reduces the amount of space being taken by data centres and company data. Q: - What is the purpose of a Hypervisor? Hypervisor is a program that manages the virtual machine. It also act like virtual machine manager that manages the many virtual machines from one place. It allows multiple operating system to share single hardware host. Each operating system in this consists of its own defined space consisting of space, memory and processor. It is used as a controller program to control host processors and resources. It separates out the layer between many operating systems so that one can't conflict with another one. Q: - How ESX server related to VMWare? ESX server is the enterprise edition of VMWare. It provides server virtualization platform that allows many operating systems to be shared together in a convenient way and consists of a centralized management platform that is also known as virtual centre. ESX server is a virtualization technique that is used to create cloud applications and allows easy development of cloud platforms. It is related to VMWare as it is the upper layer of it. Q: - What is the difference between ESX and GSX server? GSX server acts as type 2 hypervisor that gets installed on the host operating system's hardware like windows and Linux. VMWare workstation gets mixed up with GSX server to provide it more functionality to run your applications and operating systems. ESX server on the other hand, is type 1 hypervisor that runs its software directly on the system's hardware and it doesn't require any operating system prior to its installation. It is level 0 hypervisor and it has its own operating system. Q: - How VMWare Kernel different from other kernels? VMWare kernel is a proprietary kernel that means that it is a registered kernel by VMWare Company and it is not based on any other kernel architecture or any other operating system. VMWare consists of a kernel that requires an operating system to boot it. A service console is being provided when VMWare kernel is booted. Q: - What are the features provided by VMWare for easy access? VMWare provides several features to make it easy for the user to access and maintain it. The features are as follows: VMWare provides web browser interface A. It provides easy to use wizard to configure the settings B. It provides tools to easily create hosts and maintain it from one place C. It provides easy maintenance of Virtual machines D. It provides easy graphics to configure the VMWare settings for security
  • 18. 18 Q: - What are the different components used in VMWare infrastructure? The different and major components used in VMWare infrastructure is as follows: 1. VMWare infrastructure consists of the lowest layer which acts as a ESX server host. 2. VMWare infrastructure also use the virtual centre server that keep tracks of all the VM related images and manage it from one point. 3. VMWare infrastructure (VI) client: this allows the client to interact with user's applications that are running on VMWare. 4. Web browser is used to access the virtual machines. 5. License server is used to create a server that provides licensing to the applications 6. Database servers are used to maintain a database. Q: - What is QEMU? QEMU is a generic and open source machine emulator and virtualizer. When used as a machine emulator, QEMU can run OS and programs made for one machine (e.g. an ARM board) on a different machine (e.g. your own PC). By using dynamic translation, Qemu achieves very good performance. Q: - What is KVM (Kernel Virtual Machine ) KVM is a Linux kernel module that allows a user space program to utilize the hardware virtualization features of various processors. Q: - Difference Between Qemu and KVM Q: - Define snaphot of a virtual Machine ? A snapshot is the state of a virtual machine and generally, its storage devices, at an exact point in time. Snapshots are taken by simply giving an order to do so at a given time, and can be "reverted" to on demand, with the effect that the VM appears exactly as it did when the snapshot was taken. Snaphot is useful as an extremely rapid backup technique, prior to a risky operation. Q: - What is memory virtualization ? Memory virtualization, aggregating random-access memory (RAM) resources from networked systems into a single memory pool. QEMU KVM 1. Qemu is a complete and standalone software ,it emulates the target operating system. 2. Qemu supports Para virtualization 3. To emulate more than just the processor, Qemu includes a long list of peripheral emulators: disk, network, VGA, PCI, USB, serial/parallel ports, etc. 1. KVM supports full virtualiztion 2. KVM is a fork of the Qemu executable ,Both teams work actively to keep difference at a minimum 3. Apart from the processor state switching, the kernel module also handles a few low-level parts of the emulation, like the MMU registers (used to handle VM) and some parts of the PCI emulated hardware.
  • 19. 19 Q: - What is Stoarge Virtualization Storage virtualization, the process of completely abstracting logical storage from physical storage.Virtual disk drive, a computer program that emulates a disk drive such as a hard disk drive or optical disk drive in virtualized setup. Q: - What is virtual Machine Cloning ? Virtual Machine Cloning is a method of creating a copy of an existing virtual machine with the same configuration and installed software as the original.The existing virtual machine is called the parent of the clone. When the cloning operation is complete, the clone is a separate virtual machine. Q: - What are the types of cloning in virtualization ? A full clone is an independent copy of a virtual machine that shares nothing with the parent virtual machine after the cloning operation. Ongoing operation of a full clone is entirely separate from the parent virtual machine. A linked clone is a copy of a virtual machine that shares virtual disks with the parent virtual machine in an ongoing manner. This conserves disk space, and allows multiple virtual machines to use the same software installation. Q: - What is Data encryption? Data encryption ensures data safety and very important for confidential or critical data. It protect data from being read, altered or forged while transmission. Q: - What is the Public Key Encryption? Public key encryption use public and private key for encryption and decryption. In this mechanism, public key is used to encrypt messages and only the corresponding private key can be used to decrypt them. To encrypt a message, a sender has to know recipient's public key. Q: - What is Digital Signatures ? Digital signature is an attachment to an electronic message used for security purpose. It is used to verify the authenticity of the sender. Q: - What are Brute Force Attacks? Brute forcing is a mechanism which is used by an attacker to break the encryption of data by applying a set of various key. Cryptanalyst has a set of number of keys and apply them one by one to the encryption algorithm until he get the right key. Example: http://www.abc.com/online/Displaymsg.asp?msgID=87951 In this example a cryptanalyst may apply bruteforcing to the value of msgID and read the user’s data. In this the browser requesting for Displaymsg.asp page and sending msgID 87951 to the web server. Q: - How do you use RSA for both authentication and secrecy? RSA is a public key encryption algorithm. The RSA algorithms are based on the mathematical part that it is easy to find and multiply large prime numbers together, but it is extremely difficult to factor their product. For authentication: One can encrypt the hash (MD4/SHA) of the data with a private key. This is known as digital signature. For Secrecy: Secrecy/confidentiality is achieved by encrypting the data with public key and decrypting with private key.
  • 20. 20 Q: - If you are a victim of Denial of Service (Dos) then what you do? The function of a denial of service attack is to flood its target machine with too much traffic and prevents it from being acc essible to any other requests or providing services. To prevent DoS attacks firewall can be configured as a relay; in this approach the firewall responds on behalf of the internal host. During the attack, the firewall responds to the SYN sent by the attacker; since the ACK never arrives, the firewall terminates the connection. By Keeping protocols and Antivirus software up-to-date, we can prevent to be a victim of DoS. A regular scanning of the machine is also necessary in order to detect any “anomalous― behavior. Q: - What are the differences among encoding, encryption and hashing? Encoding: Basically encoding is used to protect the integrity of data as it crosses through communication network to keep its original message upon arriving. It is primarily an insecure function because it is easily reversible. Encryption: Encryption is basically designed for confidentiality and data integrity and reversible only if you have the appropriate key. Hashing: With hashing the operation is one-way i.e. non-reversible. It takes an input (or ,message ) and returns a fixed- size string, which is called the hash value. Q: - if We have to generate a hash function then what characteristics are needed in a secure hash function? A secure hash function should have the following characteristics: I. The output generated by a hash function should be of a fixed length. II. It should be very easy to find out a hash function for a given message. II. If a hash value is given of a message than it is almost impossible to get that message. V. The two different messages should not have the same hash value; it is against the hash function property. Q: - What is Authentication Header and how it provides the protection to IP header? Basically Authentication Header protects IP header and provides the complete authenticity to the IP packets. AH may work in two ways: transport mode and tunnel mode. In tunnel mode; AH protects the IP header using two IP header layers inner and outer. Inner IP header is used to contain the source and destination addresses, and the outer IP header is used to contain the security gateway information. Q: - What is the difference between a hub, a switch, and a router? A hub is a small, simple, low-priced device that joins multiple computers together. A switch is a small hardware device that joins multiple computers together within one local area network (LAN) and they operate at layer 2 of the OSI model. Routers are the physical devices that join multiple wired or wireless networks together and they operate at layer 3 of OSI model. Q: - What meaning has ICMP? The Internet Control Message Protocol or ICMP is belonging to the TCP/IP set and has the role of testing the notifications transmissions of hosts and gateways and manages the messages of error and control. Q: - How is UDP different from TCP? While TCP is a network protocol that is based on connection, UDP is not connection based. Connection means that the transfer of data between two points on a network is made with the acknowledgement of the success of the process. TCP is
  • 21. 21 used if we want to transfer data and receive confirmation that the data was really sent, no matter in what time period it was made. For example UDP is used when a movie is streamed and we need continuous frame play without interruptions. Q: - What was the strangest situation that you had to deal with regarding managing a network? The candidate will answer to this question mentioning an experience in which he/she had difficulties being understood by the other workers in the company and his/her suggestions were not followed as they were explained, leading to a network fail or other severe problems. Q: - Please tell us some job specific tasks that you have performed in your previous organization? The profession specific tasks that I have performed include installing the original, new version software, keeping record of all the changes to the network environment, managing local area network and providing backup. I had also supervised all the activities on the network and developed management information solutions by using business objects. Q: - What are your technical and non-technical skills? Well, I have 8 year experience as network manager. During the entire course of my profession I have acquired various technical and non-technical skills. I have gained good logical and technical knowledge of networking and software. I have intensive knowledge of Oracle database systems, design, crystal reports and .NET. Apart from this, I have excellent communication and interpersonal skills and I have the ability to function successfully in both team and independent work environments. Q: - How a network maintenance operation is made? The maintenance of a network is made by running tests for the purpose of detecting viruses, breakdowns, hackers or bugs. A network administrator should always stay updated with the latest technology and this can be made only through constant market research. Staying up-to-date helps the administrator to improve the network and to maintain it in a good state all the time. Q: - What is the meaning of a database server? When a database server exists, it receives the SQL requests in form of messages and each SQL reaches the entire network. The data is processed by the server itself and doesn’t have to be returned to the client for processing. This makes things more efficient. Q: - Which are, in your opinion the best traits of a network administrator? The guys that are involved in network administration in most cases they are natural fixers, they were passionate about computers since they were kids and they know when a problem appears before it makes much damage, they are able to prevent it so it is not necessary to repair it. Q: - How can you explain the meaning of a Remote Procedure Call or RPC? A Remote Procedure Call makes the complexity of the network hidden. It actually invokes a remote server function and closes itself until the results come back. This process is a synchronous one.
  • 22. 22 Q: -What is the meaning of Middleware? For the good communication between servers and clients there is a software called Middleware. Its behavior is just like the one of a bridge. The application from the client calls a service and Middleware manages the transfer through the network and receiving results. Middleware doesn’t contain any additional software, the other applications are found on the server or on the client. Q: - Do you difficult for a network administrator to stay so much in front of the computer? When a person decides to become a network administrator he/she must be aware that physical effort will not take part of the job and even if it is , in rare occasions, it is minimal. The work of a network administrator resumes to doing different tasks on the computer and giving phone calls for support. In rare occasions he may act as a system administrator but this is due to urgency. Q: - What is an object server doing? With the aid of an object server the application from the client or from the server is a group of communicating objects. The Objects Request Broker or ORB facilitates the communication between client objects and server objects. Q: - What is the difference between these three: encryption, encoding and hashing? Encryption is used for keeping data intact and safe and is not so easy to reverse because it requires a certain key. Encoding is used to protect data as it passed through the network and after reaching the destination the data returns to the initial state because it is easy reversible process; being easy reversible makes it not so good for data protection. Hashing is a protection method that is not reversible and the data comes under the form of a string named the hash value. Q: - How can we explain the following terms: gateway and router? A gateway is like a door that opens for a data package to exit the interior network and step outside the network. The Router handles the transportation of data packages over the interior network. Q: - What is the way in which the Asynchronous Transfer Mode works? The Asynchronous Transfer Mode or ATM is a connection technology that works by transmitting data into organized 53 bytes (small) packages through a physical environment with a high efficiency. Packing data into small cells reduces transportation delay so the speeds reached by this technology are very high; it can reach even 10 Gb per second. Q: - What types of Transmission media do exist? The signals transported through Transmission media care have two types: Guided media Guided media are the conduit types that allow transmission through coaxial cables, fiber optics and twisted-pairs. In this type of transmission the data flow is dependable of the physical limits of the conducting material. The signal is transported over the metallic conductor as an electric current, this is the case for coaxial cables and twisted pairs. In the case of fiber optics lights signals are transmitted through a plastics or glass cable. Unguided media This type refers to wireless communication which uses the air to propagate the signal, along with the cellular phone technology, satellite technology and radio technology. The signal takes the form of electromagnetic waves and travels on the air without the need of a solid conductor.
  • 23. 23 Q: - What is a broadcast storm? We say we have a broadcast storm when the traffic or broadcasting on the network has reached certain limits, meaning that it’s overwhelmed and this can make the network loose the connection. In order for the network to be protected against broadcast storm a firewall must be installed. Q: - What is a NIC and what is it used for? NIC stands for Network Interface Card. It is connected to the motherboard of the computer. It provides the device with a MAC address and allows a device to access a computer network such as the internet. Q: - Define broadcast domain. It is a logical area in a computer network where any computer connected to the network can directly transmit to any other computer in the domain without having to go through a routing device. Q: - What is bridge and switch ? A bridge connects two different LAN networks. A switch is something like you can connect many computers to a switch and then one computer can connect to another through the switch. Switch is a unicast one to one connection. Q: - What is a Router? A router is a device or sometimes a software in a computer which decides the next network point to which a packet should be forwarded to reach its destination on Internet. It is usually included as part of the network switch and is located at a gateway, including each point-of-presence on the Internet. The router is connected to at least two networks and determines which way to send each information packet based on its understanding of the state of the networks it is connected to. Q: - What is Ethernet technology? Ethernet technology is a high speed broadcast bus technology. In this type, all the station shares a single ether channel and receives every single transmitted signal. Q: - Explain token ring technology. In this technology, all the devices are arranged in a circle. A token moves around the circular network. A device waits for the token before it sends its frame. Once it receives token, it initiates transmission of its frame. Q: - What is CSMA and CD concept? In CSDA (carrier sense multiple access), presence of any digital signal in a network is checked before transmission. Data transmission occurs only when no signal is sensed. CD, Collision detection is responsible for monitoring carrier in order to avoid signal jam.
  • 24. 24 Q: - What is IGMP protocol? Internet Group Management Protocol, allows internet hosts to multicast. i.e. to send messages to a group of computers. There may be a group of internet hosts interested to multicast. IGMP allows router to determine which host groups have members on a given network segment. It helps to establish group memberships. It is commonly used for streamlining videos and gaming. The protocol can be implemented both as a host side and router side. The host side is responsible to notify its membership in a group. The notification is made to a local router. This local router (router side) in turn sends out queries. Q: - What is Router? Explain components of Routers? The way switches connect multiple computers, a router connects multiple networks. Routers comprise of data consisting of large tables of networks and addresses. Routers use algorithms to determine the shortest route to an address in a network. Q: - Explain the difference between switch and Hub? HUb: limited port compare to switch.less speed compare to switch because more collision. Hub is a layer-1 device,in this data transmission in the form of bits.It is used to connect the computers and it gives the acknowledgment for received data Switch: To Avoid collision we use switch. In switch Each Port having own collision Domain.Switch is a layer-2 device,in this data transmission in the form of frames. In swaitch bi directional information. It exchanges the data. Q: - What is a VLAN? What does VLAN provide? A technology called VLAN (Virtual LAN broadcast domains logically segmented on an Ethernet switch) trunking that was once primarily the domain of network switches has now trickled down to the rest of the Data Center to address these issues. Now it is possible for these multi-homing devices to be multi-homing in function without the need for multiple physical network adapters and the additional infrastructure associated with them. VLAN trunking allows a single network adapter to behave as n number of virtual network adapters, where n has a theoretical upper limit of 4096 but is typically limited to 1000 VLAN network segments. In the case where a single gigabit Ethernet adapter is trunked in place of using multiple FastEthernet adapters, higher performance at a lower cost while increasing flexibility can be achieved. Q: - What is the use of HUB ? A common connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports. When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets. Q: - What is Passive Hub? A passive hub serves simply as a conduit for the data, enabling it to go from one device (or segment) to another. So-called intelligent hubs include additional features that enables an administrator to monitor the traffic passing through the hub and to configure each port in the hub. Intelligent hubs are also called manageable hubs. Q: - What is Switch Hub ? Switching hub, actually reads the destination address of each packet and then forwards the packet to the correct port.
  • 25. 25 Q: - What are advantages and disadvantages of a Hub ? Hub Advantages:- Visibility: Using an hub allows us to eaves-drop on conversations with a network protocol analyzer, often called a "sniffer". Cost: Because hubs are less complicated, they tend to cost less per port than switches. Hub disadvantages:-Because they repeat all traffic they receive on all attached ports each connected NIC will have a more difficult time getting its traffic onto the network. Whenever one NIC sends a message, all others must wait for it to pass before they get their own message onto the network. Q: - What is a Switch ? In networks, a device that filters and forwards packets between LAN segments. Switches operate at the data link layer (layer 2) and sometimes the network layer (layer 3) of the OSI Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs. Q: - How does a switch work ? A switch,keeps a record of the MAC addresses of all the devices connected to it. With this information, a switch can identify which system is sitting on which port. So when a frame is received, it knows exactly which port to send it to, without significantly increasing network response times. And, unlike a hub, a 10/100Mbps switch will allocate a full 10/100Mbps to each of its ports. So regardless of the number of PCs transmitting, users will always have access to the maximum amount of bandwidth. It's for these reasons why a switch is considered to be a much better choice then a hub. Q: - What are the type of network switches ? Unmanaged Network Switches :- Unmanaged network switches are commonly used in home networks and small businesses. It allows devices on the network to communicate with each other, such as computer to computer or printer to computer. An unmanaged switch does not need to be monitored or configured using external software applications. They are easy to set up and require only cable connections. Unmanaged network switches are ideal for small and medium networks. Managed Switches :- Managed switches can be modified to suit the functionality of a particular network. They are managed by an embedded simple network management protocol (SNMP), secure shell or via a serial console. There are two types ofmanaged switches: smart switches and enterprise managed switches. Smart switches fall between unmanaged and managed switches. They offer most of the features of managed switches without their cost or complexity. A smart switch is able to configure virtual LANs, ports and set up trunking. Smart switches are ideally used in fast LANs, which are those that support gigabit data transfer. Enterprise managed switches are also called fully managed switches. They have a wide range of management features, including a web interface, SNMP agent and command-line interface. Additional features include the ability to restore, backup, modify and display configurations. They have more features than traditional managed and unmanaged switches and are generally more expensive. They are found in large enterprises, which are comprised of a large number of connections and nodes. Q: - What are the typical switch management features ? a) Turn particular port range on or off b) Link bandwidth and duplex settings c) Priority settings for ports d) IP Management by IP Clustering. e) MAC filtering and other types of "port security" features which prevent MAC flooding f) Use of Spanning Tree Protocol
  • 26. 26 g) SNMP monitoring of device and link health h) Port mirroring (also known as: port monitoring, spanning port, SPAN port, roving analysis port or link mode port) i) Link aggregation (also known as bonding, trunking or teaming) j) VLAN settings k) 802.1X network access control l) IGMP snooping Q: - Explain traffic monitoring on a switched network ? Two popular methods that are specifically designed to allow a network analyst to monitor traffic are: Port mirroring — the switch sends a copy of network packets to a monitoring network connection. SMON — "Switch Monitoring" is described by RFC 2613 and is a protocol for controlling facilities such as port mirroring. Another method to monitor may be to connect a layer-1 hub between the monitored device and its switch port. This will induce minor delay, but will provide multiple interfaces that can be used to monitor the individual switch port. Q: - what are the advantages and disadvantages of network switch ? Switch Advantages :- Client Performance: Because any given system attached to a switch sees only information explicitly addressed to its NIC, there is less overhead time spent throwing away packets that it does not need to read. Higher Throughput: Because only relevant traffic is sent down any given network port, each NIC gets its own packets delivered to the switch independently of each other NIC attached to that switch. This means a switch can manage a larger total volume of data in transit at any given time. Switch Disadvantages :- Unless the switch is expensive enough to include "port mirroring" capability, a sniffer is of limited use on a switch because the switch automatically filters out the traffic the sniffer would like to get Q: - What are the pre requisites to install Exchange Server 2007? 1. Microsoft .Net Framework 2.0 2. Microsoft ASP .Net 3. World Wide Web Service 4. MMC 3.0 5. Windows power shell 6. SMTP & NNTP service should not be installed Q: - What is the order to install Exchange Server 2007 Roles in a exchange Server 2003 organization? 1. Client Access Server Role 2. Hub Transport Server Role 3. Mailbox Server Role 4. Unified Messaging Server role Q: - What are the versions available in Exchange Server 2007? There are two types of Exchange Server 2007 version release 64 bit for production environment 32 bit only for non-production environment
  • 27. 27 Q: - What are the Operating system requirements to install Exchange Server 2007? Exchange Server 2007 can be installed on Windows Server 2003 SP2 64-bit, Windows Server 2003 R2 SP2 64-bit or Windows Server 2008 64-bit Q: - What are the Active directory requirements to install Exchange Server 2007? 1. Domain functional level at least windows server 2000 native or higher 2. Schema Master must be run on windows 2003 server with sp1 3. At least one Domain Controller, in each domain with windows server 2003 sp1 4. At least one global catalog server in Active Directory Site which hosts exchange Server 2007 5. 4:1 ratio of Exchange processor to global catalog server processors Q: - What are the hardware requirements to install Exchange Server 2007? * Processor – 64 bit processor * RAM – 2 GB + 5 MB per Mailbox * Disk Space – At least 1.2 GB on the drive on which you install Exchange * 200 MB of available disk space on the system drive * File Format – NTFS Q: - What are the Software requirements to install Exchange Server 2007? Following are the software prerequisites to install Exchange Server 2007 1. Microsoft .Net Framework 2.0 2. IIS 3. WWW 4. MMC 3.0 5. Microsoft Windows Power Shell Q: - What is Transition in Exchange Server 2007? Transition is the scenario in which you upgrade an existing Exchange organization to Microsoft Exchange Server 2007. To perform the transition, you must move data from the existing Exchange servers to new Exchange 2007 servers. For example, when upgrading from an Exchange Server 2003 or Exchange 2000 Server organization to an Exchange 2007 organization, you perform a transition. When transitioning to Exchange 2007, you cannot perform an in-place server upgrade on an existing Exchange server. Instead, you must install a new Exchange 2007 server into the existing organization, and then move data to the new Exchange 2007 server. Q: - What is Migration in Exchange Server 2007? Migration is the scenario in which you upgrade to Exchange 2007 by migrating data from a non-Exchange messaging system to Exchange 2007 or from an existing Exchange organization to a completely new Exchange organization, without retaining any of the Exchange configuration data in the first organization. For example, when merging with another company, you can perform a migration. In this scenario, you move mailboxes and data to the other company’s Exchange organization, without retaining any of the configuration data from your existing Exchange organization. Another example is when upgrading from Lotus Notes to Exchange 2007, you perform a migration. In this scenario, you must move
  • 28. 28 mailboxes and data to the new Exchange 2007 organization, without retaining any of the data from the Lotus Notes organization. The migration process includes installing a completely new Exchange 2007 organization, and then migrating mailboxes from the old messaging system to the new Exchange 2007 messaging system, using various tools for migration. Q: - Is it possible to do in place upgrade from Exchange Server 2003 to Exchange Server 2007? No in-place upgrade on existing Exchange server organization. Install new Exchange Server 2007 server into existing organization, and move data to new server. Q: - What are the transition options available in Exchange Server 2007 We can make transition in following options Single forest to single forest you have an existing single forest Exchange 2003 or Exchange 2000 topology, you can transition to a single forest Exchange 2007 organization Single forest to cross forest sIf you have an existing single forest Exchange 2003 or Exchange 2000 topology, you can transition to a cross-forest Exchange 2007 topology Cross forest to cross forest If you have an existing cross-forest Exchange 2003 or Exchange 2000 topology with Exchange servers and mailboxes in each forest, you can transition to an Exchange 2007 cross-forest topology. Resource forest to resource forest - Single forest to resource forest - Q: -What are the considerations for Exchange Server 2007 to co exists with Exchange server 2000 and Exchange Server 2003? * Exchange Organization in Exchange Native Mode· Exchange Server 2007 routing group (DWBGZMFD01QNBJR) is created only for coexisting with earlier versions of Exchange. * Routing Group Connector is required between Exchange Server 2003 and Exchange Server 2007 (created during setup). * Exchange Server 2003 computers cannot interoperate with the Unified Messaging server role. Exchange 2003 mailboxes cannot be Unified Messaging–enabled. * Exchange 2003 Front-ends cannot talk to Exchange Server 2007 Mailbox Server Roles. * No in-place upgrade on existing Exchange server. Install new Exchange Server 2007 server into existing organization, and move data to new server Q: - Will Front End server talk to Exchange Server 2007 Mailbox server in an Exchange organization having both exchange 2003 and exchange Server 2007? Exchange Server 2003 Front-end server cannot talk to Exchange Server 2007 Mailbox Server Roles Q: - What is the status of routing group connector in co existed of Exchange Server 2003 and 2007? Exchange Organization in Exchange Native Mode· Exchange Server 2007 routing group (DWBGZMFD01QNBJR) is created only for coexisting with earlier versions of Exchange. Routing Group Connector is required between Exchange Server 2003 and Exchange Server 2007 (created during setup). Q: - Which service should not be installed in Exchange Server 2007 installation? SMTP and NNTP service should not be installed
  • 29. 29 Q: - What are the Exchange Server editions available? There are two types of Exchange Server 2007 editions available 1. Standard Edition 2. Enterprise Edition Q: - What is the difference between standard and Enterprise Edition? Exchange 2007 functions Standard Edition Enterprise Edition Number of Data Stores Supported Q: - What to do if exchange Server 5.5 in your organization in order to upgrade to Exchange Server 2007? You cannot upgrade an existing Microsoft Exchange Server version 5.5 organization to Exchange Server 2007. You must first migrate from the Exchange Server 5.5 organization to an Exchange Server 2003 or an Exchange 2000 Server organization. Then you can transition the Exchange 2003 or Exchange 2000 organization to Exchange 2007. Q: - What are the Planning Considerations of Mailbox Server Role? The Microsoft Exchange Server 2007 Mailbox server role hosts mailbox databases and provides e-mail storage and advanced scheduling services for Microsoft Office Outlook users The Mailbox server role can also host a public folder database, which provides a foundation for workflow, document sharing, and other forms of collaboration We have to perform a planning consideration on * Sizing the database, * Planning for public folder, * Co hosting with other server roles and * Planning for clustered Mailbox server Q: - What are the Planning considerations for Client Access Server Role? The Client Access server role supports the Outlook Web Access, Outlook Anywhere, and Exchange ActiveSync client applications, in addition to the POP3 and IMAP4 protocols. The Client Access server role also hosts several key services, such as the Auto discover service and Exchange Web Services. In order to have better client access functionality we have to perform a Planning consideration on Exchange Active Sync. Outlook web Access, outlook anywhere, POP3 and IMAP4 protocols and also securing client access Q: - What are the Planning Considerations of Hub Transport Server Role? Hub Transport server role is a required role in a Microsoft Exchange Server 2007 organization that provides routing within a single organizational network by using the Active Directory directory service site. Hub Transport server role installed handles all mail flow inside the organization, apply transport rules, apply journal rules, and deliver messages to recipients’ mailboxes We have to perform a Planning Consideration on * Topology for mail flow inside and outside the Exchange organization * Server capacity – determine how to perform performance monitor * Security – includes delegation of administrative roles and verification that IP connections are only enabled from authorized servers
  • 30. 30 * Transport Features – determine the transport features that you will enable at the Hub Transport server and how they will be configured Q: - What are the Planning Considerations for Edge Transport Server Role? Exchange Server 2007 Edge Transport server role is designed to provide improved antivirus and anti-spam protection for the Exchange organization. Computers that have the Edge Transport server role also apply policies to messages in transport between organizations. The Edge Transport server role is deployed in an organization’s perimeter network. * Edge Transport Should not be included in Active Directory * Should be installed in a Standalone Server * Edge Transport Should not be Part of the domain * ADAM Should be Installed * Pre requisites .Net framework , Windows Management Shell, MMC