Network management is the discipline in computing dealing with operating, managing and monitoring voice anddata networks.N...
Advantages of network configuration management include:        Streamlining the processes of maintenance, repair, expansio...
OSI Ref.         OSI Layer                   TCP/IP             TCP/IP Protocol ExamplesLayer No.        Equivalent       ...
ICMP ProtocolThe Internet Control Message Protocol (ICMP) detects and reports network error conditions. ICMP reports on th...
Application LayerThe application layer defines standard Internet services and network applications that anyone can use. Th...
/etc files – The original host-based UNIX name system was developed for standalone UNIX machines and then     adapted for ...
to refer to the complete collection of management information available on an entity, it is often used to refer to apartic...
Subnet MaskPerhaps the most recognizable aspect of subnetting is the subnet mask. Like IP addresses, a subnet mask contain...
command that modifies the MIF as needed and the Event command that notifies management    software of critical events.    ...
RIP implements the split horizon, route poisoning and holddown mechanisms to prevent incorrectrouting information from bei...
Support for SNMPDMI can co-exist with SNMP. A single machine can serve as a proxy agent to service an entire LAN segment o...
. If you are connecting to non-Cisco devices.. Security. CDP broadcasts information about the device every 60 seconds. Sni...
The show cdp neighbors command displays the following:· Device ID (name of the device)· The local interface (local outgoin...
· Device platform and capabilities· Local interface and outgoing port ID· Remote device holdtime in seconds· IOS type and ...
Hdr syntax: 0, Chksum error: 0, Encaps failed:No memory: 0, Invalid packet: 0, Fragmented: 0What does the show cdp interfa...
The show sessions command displays the active outbound telnet sessions from that particular useron your router.RouterA#sho...
·IWhat does each of these responses mean?. = Each period indicates that the network server timed out while waiting for a r...
What is the function of ROM on a Cisco router?On a Cisco router, ROM is used to start and maintain the router.What is Flas...
What Cisco IOS command displays the contents of Flash memory?The show flash command displays the contents of Flash memory....
Erasing the nvram filesystem will remove all files! Continue? [confirm][OK]Erase of nvram: completeNote: In order to compl...
Source filename [routerb-flash]? flash:c2500-d-l.120-13.binAddress or name of remote host []? 192.168.0.2Destination filen...
routed protocolsenable passwordImportant Config Register Notes:2100 manual boot rommon>2101 boot from ROM2102 normal/passw...
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Network management

  1. 1. Network management is the discipline in computing dealing with operating, managing and monitoring voice anddata networks.Network management is often defined as consisting of five areas, using the acronym FCAPS: Fault Management Configuration Management Accounting (Administration) Performance Management Security Management.Fault ManagementFault management is the component of network management concerned with detecting, isolatingand resolving problems. Properly implemented, fault management can keep a network running at anoptimum level, provide a measure of fault tolerance and minimize downtime. A set of functionsor applications designed specifically for this purpose is called a fault-management platform.Important functions of fault management include: Definition of thresholds for potential failure conditions. Constant monitoring of system status and usage levels. Continuous scanning for threats such as viruses and Trojans. General diagnostics. Remote control of system elements including workstations and servers from a single location. Alarms that notify administrators and users of impending and actual malfunctions. Tracing the locations of potential and actual malfunctions. Automatic correction of potential problem-causing conditions. Automatic resolution of actual malfunctions. Detailed logging of system status and actions taken.Configuration ManagementNetwork configuration management (NCM) is the process of organizing and maintaining informationabout all the components of a computer network. When a network needs repair, modification,expansion or upgrading, the administrator refers to the network configuration managementdatabase to determine the best course of action. This database contains the locations and networkaddresses of all hardware devices, as well as information about the programs, versions and updatesinstalled in network computers.Network configuration management tools can be vendor-neutral or vendor-specific. Vendor-neutraltools, by far the more common, are designed for networks containing hardware and programs frommultiple suppliers. Vendor-specific tools usually work only with the products of a single company,and can offer enhanced performance in networks where that vendor dominates.
  2. 2. Advantages of network configuration management include: Streamlining the processes of maintenance, repair, expansion and upgrading. Minimizing configuration errors. Minimizing downtime. Optimizing network security. Ensuring that changes made to a device or system do not adversely affect other devices or systems. Rolling back changes to a previous configuration if results are unsatisfactory. Archiving the details of all network configuration changes.Accounting ManagementAccounting management is the process used to measure network utilization parameters so that individual or group users on thenetwork can be regulated appropriately for the purposes of accounting or chargeback. Similar to performance management, thefirst step toward appropriate accounting management is to measure the utilization of all important network resources. Networkresource utilization can be measured using the Cisco NetFlow and Cisco IP Accounting features. Analysis of the data gatheredthrough these methods provides insight into current usage patterns.A usage-based accounting and billing system is an essential part of any service level agreement (SLA). It provides both apractical way of defining obligations under an SLA and clear consequences for behavior outside the terms of the SLA. Performance Management SystemsSuccessful organizations know that to win in today’s competitive marketplace they must attract, develop, andretain talented and productive employees. Winning organizations get their competitive edge from aperformance management system that helps them hire talented people, place them in the right position, aligntheir individual performance with the organization’s vision and strategic objectives, develop their abilities,and reward performance commensurate with contributions to the organization’s success.Benefits of Effective Performance Management Improved Productivity -- Improvement in both the way people work and the outcomes they produce. Improved Employee Morale -- Resulting from on-time performance appraisals and rewards commensurate with employee contributions. Retention of Top Performers – Employees who feel accomplished in their work become loyal employees. Increased Profitability – Loyal employees deliver higher levels of service that result in customer loyalty.TCP/IP Protocol Architecture ModelThe OSI model describes idealized network communications with a family of protocols. TCP/IP does not directly correspond tothis model. TCP/IP either combines several OSI layers into a single layer, or does not use certain layers at all. The followingtable shows the layers of the Oracle Solaris implementation of TCP/IP. The table lists the layers from the topmost layer(application) to the bottommost layer (physical network).Table 1–2 TCP/IP Protocol StackOSI Ref. OSI Layer TCP/IP TCP/IP Protocol ExamplesLayer No. Equivalent Layer5,6,7 Application, session, Application NFS, NIS, DNS, LDAP, telnet, ftp, rlogin, rsh, rcp, presentation RIP, RDISC, SNMP, and others
  3. 3. OSI Ref. OSI Layer TCP/IP TCP/IP Protocol ExamplesLayer No. Equivalent Layer4 Transport Transport TCP, UDP, SCTP3 Network Internet IPv4, IPv6, ARP, ICMP2 Data link Data link PPP, IEEE 802.21 Physical Physical Ethernet (IEEE 802.3), Token Ring, RS-232, FDDI, and others networkThe table shows the TCP/IP protocol layers and the OSI model equivalents. Also shown are examples of the protocols that areavailable at each level of the TCP/IP protocol stack. Each system that is involved in a communication transaction runs a uniqueimplementation of the protocol stack.Physical Network LayerThe physical network layer specifies the characteristics of the hardware to be used for the network. For example, physicalnetwork layer specifies the physical characteristics of the communications media. The physical layer of TCP/IP describeshardware standards such as IEEE 802.3, the specification for Ethernet network media, and RS-232, the specification forstandard pin connectors.Data-Link LayerThe data-link layer identifies the network protocol type of the packet, in this instance TCP/IP. The data-link layer also provideserror control and “framing.” Examples of data-link layer protocols are Ethernet IEEE 802.2 framing and Point-to-Point Protocol(PPP) framing.Internet LayerThe Internet layer, also known as the network layer or IP layer, accepts and delivers packets for the network. This layerincludes the powerful Internet Protocol (IP), the Address Resolution Protocol (ARP), and the Internet Control Message Protocol(ICMP).IP ProtocolThe IP protocol and its associated routing protocols are possibly the most significant of the entire TCP/IP suite. IP isresponsible for the following: IP addressing – The IP addressing conventions are part of the IP protocol. Designing an IPv4 Addressing Scheme introduces IPv4 addressing and IPv6 Addressing Overview introduces IPv6 addressing. Host-to-host communications – IP determines the path a packet must take, based on the receiving systems IP address. Packet formatting – IP assembles packets into units that are known as datagrams. Datagrams are fully described in Internet Layer: Where Packets Are Prepared for Delivery. Fragmentation – If a packet is too large for transmission over the network media, IP on the sending system breaks the packet into smaller fragments. IP on the receiving system then reconstructs the fragments into the original packet.Oracle Solaris supports both IPv4 and IPv6 addressing formats, which are described in this book. To avoid confusion whenaddressing the Internet Protocol, one of the following conventions is used: When the term “IP” is used in a description, the description applies to both IPv4 and IPv6. When the term “IPv4” is used in a description, the description applies only to IPv4. When the term “IPv6” is used in a description, the description applies only to IPv6.ARP ProtocolThe Address Resolution Protocol (ARP) conceptually exists between the data-link and Internet layers. ARP assists IP indirecting datagrams to the appropriate receiving system by mapping Ethernet addresses (48 bits long) to known IP addresses(32 bits long).
  4. 4. ICMP ProtocolThe Internet Control Message Protocol (ICMP) detects and reports network error conditions. ICMP reports on the following: Dropped packets – Packets that arrive too fast to be processed Connectivity failure – A destination system cannot be reached Redirection – Redirecting a sending system to use another routerInternet Control Message ProtocolFrom Wikipedia, the free encyclopediaThe Internet Control Message Protocol (ICMP) is one of the core protocols of the Internet Protocol Suite. It is chiefly used bythe operating systems of networked computers to send error messages indicating, for example, that a requested service is notavailable or that a host or router could not be reached. ICMP can also be used to relay query messages.[1] It is assignedprotocol number 1.[2]ICMP[3] differs from transport protocols such as TCP and UDP in that it is not typically used to exchange data between systems,nor is it regularly employed by end-user network applications (with the exception of some diagnostic toolslike ping and traceroute).ICMP for Internet Protocol version 4 (IPv4) is also known as ICMPv4. IPv6 has a similar protocol, ICMPv6.Transport LayerThe TCP/IP transport layer ensures that packets arrive in sequence and without error, by swapping acknowledgments of datareception, and retransmitting lost packets. This type of communication is known as end-to-end. Transport layer protocols atthis level are Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and Stream Control Transmission Protocol(SCTP). TCP and SCTP provide reliable, end-to-end service. UDP provides unreliable datagram service.TCP ProtocolTCP enables applications to communicate with each other as though they were connected by a physical circuit. TCP sendsdata in a form that appears to be transmitted in a character-by-character fashion, rather than as discrete packets. Thistransmission consists of the following: Starting point, which opens the connection Entire transmission in byte order Ending point, which closes the connection.TCP attaches a header onto the transmitted data. This header contains many parameters that help processes on the sendingsystem connect to peer processes on the receiving system.TCP confirms that a packet has reached its destination by establishing an end-to-end connection between sending andreceiving hosts. TCP is therefore considered a “reliable, connection-oriented” protocol.SCTP ProtocolSCTP is a reliable, connection-oriented transport layer protocol that provides the same services to applications that areavailable from TCP. Moreover, SCTP can support connections between systems that have more than one address,or multihomed. The SCTP connection between sending and receiving system is called an association. Data in theassociation is organized in chunks. Because SCTP supports multihoming, certain applications, particularly applications used bythe telecommunications industry, need to run over SCTP, rather than TCP.UDP ProtocolUDP provides datagram delivery service. UDP does not verify connections between receiving and sending hosts. BecauseUDP eliminates the processes of establishing and verifying connections, applications that send small amounts of data useUDP.
  5. 5. Application LayerThe application layer defines standard Internet services and network applications that anyone can use. These services workwith the transport layer to send and receive data. Many application layer protocols exist. The following list shows examples ofapplication layer protocols: Standard TCP/IP services such as the ftp, tftp, and telnet commands UNIX “r” commands, such as rlogin and rsh Name services, such as NIS and the domain name system (DNS) Directory services (LDAP) File services, such as the NFS service Simple Network Management Protocol (SNMP), which enables network management Router Discovery Server protocol (RDISC) and Routing Information Protocol (RIP) routing protocolsStandard TCP/IP Services FTP and Anonymous FTP – The File Transfer Protocol (FTP) transfers files to and from a remote network. The protocol includes the ftpcommand and the in.ftpd daemon. FTP enables a user to specify the name of the remote host and file transfer command options on the local hosts command line. The in.ftpd daemon on the remote host then handles the requests from the local host. Unlike rcp,ftp works even when the remote computer does not run a UNIX based operating system. A user must log in to the remote system to make an ftp connection, unless the remote system has been configured to allow anonymous FTP. You can obtain an enormous amount of material from anonymous FTP servers that are connected to the Internet. Universities and other institutions set up these servers to offer software, research papers, and other information to the public domain. When you log in to this type of server, you use the login name anonymous, hence the term “anonymous FTP server.” Using anonymous FTP and setting up anonymous FTP servers is outside the scope of this manual. However, many books, such as The Whole Internet Users Guide & Catalog, discuss anonymous FTP in detail. Instructions for using FTP are in System Administration Guide: Network Services. The ftp(1) man page describes all ftp command options that are invoked through the command interpreter. Theftpd(1M) man page describes the services that are provided by the in.ftpd daemon. Telnet – The Telnet protocol enables terminals and terminal-oriented processes to communicate on a network that runs TCP/IP. This protocol is implemented as the telnet program on local systems and the in.telnetd daemon on remote machines. Telnet provides a user interface through which two hosts can communicate on a character-by-character or line-by-line basis. Telnet includes a set of commands that are fully documented in the telnet(1) man page. TFTP – The Trivial File Transfer Protocol (tftp) provides functions that are similar to ftp, but the protocol does not establish ftps interactive connection. As a result, users cannot list the contents of a directory or change directories. A user must know the full name of the file to be copied. The tftp(1)man page describes the tftp command set.UNIX “r” CommandsThe UNIX “r” commands enable users to issue commands on their local machines that run on the remote host. Thesecommands include the following: rcp rlogin rshInstructions for using these commands are in the rcp(1), rlogin(1), and rsh(1) man pages.Name ServicesOracle Solaris provides the following name services: DNS – The domain name system (DNS) is the name service provided by the Internet for TCP/IP networks. DNS provides host names to the IP address service. DNS also serves as a database for mail administration. For a complete description of this service, see System Administration Guide: Naming and Directory Services (DNS, NIS, and LDAP). See also the resolver(3RESOLV) man page.
  6. 6. /etc files – The original host-based UNIX name system was developed for standalone UNIX machines and then adapted for network use. Many old UNIX operating systems and computers still use this system, but it is not well suited for large complex networks. NIS – Network Information Service (NIS) was developed independently of DNS and has a slightly different focus. Whereas DNS focuses on making communication simpler by using machine names instead of numerical IP addresses, NIS focuses on making network administration more manageable by providing centralized control over a variety of network information. NIS stores information about machine names and addresses, users, the network itself, and network services. NIS name space information is stored in NIS maps. For more information on NIS Architecture and NIS Administration, see System Administration Guide: Naming and Directory Services (DNS, NIS, and LDAP).Directory ServiceOracle Solaris supports LDAP (Lightweight Directory Access Protocol) in conjunction with the Sun Open Net Environment (SunONE) Directory Server, as well as other LDAP directory servers. The distinction between a name service and a directoryservice is in the differing extent of functionality. A directory service provides the same functionality of a naming service, butprovides additional functionalities as well. See System Administration Guide: Naming and Directory Services (DNS, NIS, andLDAP).File ServicesThe NFS application layer protocol provides file services for Oracle Solaris. You can find complete information about the NFSservice in System Administration Guide: Network Services.Network AdministrationThe Simple Network Management Protocol (SNMP) enables you to view the layout of your network and the status of keymachines. SNMP also enables you to obtain complex network statistics from software that is based on a graphical userinterface (GUI). Many companies offer network management packages that implement SNMP.Routing ProtocolsThe Routing Information Protocol (RIP) and the Router Discovery Server Protocol (RDISC) are two available routing protocolsfor TCP/IP networks. For complete lists of available routing protocols for Oracle Solaris 10, refer to Table 5–1 and Table 5–2.What is SNMP?• SNMP (Simple Network Management Protocol) is a standardproduced by working groups within the IETF (Internet EngineeringTask Force). It is published as a set of RFCs.• SNMP is more than a protocol. It is a management framework,including an architecture, an information model, managementoperations, etc.• SNMP is the most widely used management framework today, butmany other frameworks exist. Virtually all networked devices supportSNMP.• This presentation refers to SNMP version 1, unless stated otherwise.We will discuss the key extensions in versions 2 and 3.Management information baseA management information base (MIB) is a virtual database used for managing the entities in acommunications network. Most often associated with the Simple Network Management Protocol (SNMP), theterm is also used more generically in contexts such as in OSI/ISO Network management model. While intended
  7. 7. to refer to the complete collection of management information available on an entity, it is often used to refer to aparticular subset, more correctly referred to as MIB-module.Objects in the MIB are defined using a subset of Abstract Syntax Notation One (ASN.1) called "Structure ofManagement Information Version 2 (SMIv2)" RFC 2578.The software that performs the parsing is a MIBcompiler.The database is hierarchical (tree-structured) and entries are addressed through objectidentifiers. Internet documentation RFCs discuss MIBs, notably RFC 1155, "Structure and Identification ofManagement Information for TCP/IP based internets", and its two companions, RFC 1213, "ManagementInformation Base for Network Management of TCP/IP-based internets", and RFC 1157, "A Simple NetworkManagement Protocol".A management information base (MIB) is a formal description of a set of network objectsthat can be managed using the Simple Network Management Protocol (SNMP). The formatof the MIB is defined as part of the SNMP. (All other MIBs are extensions of this basicmanagement information base.) MIB-I refers to the initial MIB definition; MIB-II refers tothe current definition. SNMPv2 includes MIB-II and adds some new objects.Address Resolution ProtocolShort for Address Resolution Protocol, a network layer protocol used to convert an IP address into a physicaladdress (called a DLC address), such as an Ethernet address. A host wishing to obtain a physicaladdressbroadcasts an ARP request onto the TCP/IP network. The host on the network that has the IP address inthe request then replies with its physical hardware address.There is also Reverse ARP (RARP) which can be used by a host to discover its IP address. In this case, the hostbroadcasts its physical address and a RARP server replies with the hosts IP address.Address Resolution Protocol (ARP) is a telecommunications protocol used for resolution of networklayer addresses into link layer addresses, a critical function in multiple-access networks. ARP was [1]defined byRFC 826 in 1982. It is Internet Standard STD 37. It is also the name of the program formanipulating these addresses in most operating systems.subnet maskA mask used to determine what subnet an IP address belongs to. An IP address has two components, thenetwork address and the host address. For example, consider the IP address 150.215.017.009. Assuming this ispart of a Class B network, the first two numbers (150.215) represent the Class B network address, and thesecond two numbers (017.009) identify a particular host on this network.Subnetting enables the network administrator to further divide the host part of the address into two or moresubnets. In this case, a part of the host address is reserved to identify the particular subnet. This is easier to seeif we show the IP address in binary format. The full address is:10010110.11010111.00010001.00001001The Class B network part is:10010110.11010111and the host address is00010001.00001001If this network is divided into 14 subnets, however, then the first 4 bits of the host address (0001) are reserved foridentifying the subnet.A subnet allows the flow of network traffic between hosts to be segregated based on a network configuration. By organizinghosts into logical groups, subnetting can improve network security and performance.
  8. 8. Subnet MaskPerhaps the most recognizable aspect of subnetting is the subnet mask. Like IP addresses, a subnet mask contains four bytes(32 bits) and is often written using the same "dotted-decimal" notation. For example, a very common subnet mask in itsbinary representation11111111 11111111 11111111 00000000is typically shown in the equivalent, more readable form255.255.255.0DMI (Desktop Management Interface)Desktop Management Interface (DMI) is an industry framework for managing and keeping track ofhardware and software components in a system of personal computers from a central location. DMIwas created by the Desktop Management Task Force (DMTF) to automate system management andis particularly beneficial in a network computing environment where dozens or more computers aremanaged. DMI is hardware and operating system-independent, independent of specificmanagement protocol, easy for vendors to adopt, mappable to existing management protocols suchas the Simple Network Management Protocol (SNMP), and used on network and non-networkcomputers. DMI consists of four components: Management Information Format (MIF): An MIF is a text file that contains specific information about the hardware and software being used on a computer. An MIF file consists of one or more groups containing attributes, which describe each component. By default, each MIF file contains the standard component ID group. This group contains the product name, version, serial number, and the time and date of the last installation. The ID number is assigned based on when the component was installed in relation to other components. Manufacturers can create their own MIFs specific to a component. For example, a manufacturer might write an MIF file for a fax/modem that contains two groups: a fax group and a modem group. Some group attributes include warranty information, support phone numbers, and any errors encountered. This information is then sent to an MIF database. Service layer: The service layer is memory-resident code that acts as a mediator for the management interface and the component interface and allows management and component software to access MIF files in the MIF database. The service layer is available as an operating system add-on and is a shared resource for all programs. Because the service layer must run all the time, it is designed not to use a lot of memory. The service layer also includes a common interface called the local agent, which is used to manage individual components. Component interface (CI): The CI is an application program interface (API) that sends status information to the appropriate MIF file via the service layer. Commands include the Get and Set
  9. 9. command that modifies the MIF as needed and the Event command that notifies management software of critical events. Management interface (MI): The management software communicates with the service layer using the MI application program interface. The MI allows administrators to issue the Get and Set command and the List command that lists all the DMI-manageable devices.Internet Group Management ProtocolThe Internet Group Management Protocol (IGMP) is a communications protocol used by hosts andadjacent routers on IP networks to establish multicast group memberships.IGMP is an integral part of the IP multicast specification. It is analogousto ICMP for unicast connections. IGMP can be used for online streaming video and gaming, andallows more efficient use of resources when supporting these types of applications.IGMP is used on IPv4 networks. Multicast management on IPv6 networks is handled by MulticastListener Discovery (MLD) which uses ICMPv6 messaging contrary to IGMPs bare IP encapsulation.A network designed to deliver a multicast service using IGMP might use this basic architecture:IGMP is used between the client computer and a local multicast router. Switches featuring IGMPsnooping derive useful information by observing these IGMP transactions. Protocol IndependentMulticast (PIM) is then used between the local and remote multicast routers, to direct multicast trafficfrom the multicast server to many multicast clients. ]IGMP operates above the network layer, though it does not actually act as a transport protocol.Routing Information ProtocolThe Routing Information Protocol (RIP) is a distance-vector routing protocol, which employsthe hop count as a routing metric. RIP prevents routing loops by implementing a limit on the numberof hops allowed in a path from the source to a destination. The maximum number of hops allowed forRIP is 15. This hop limit, however, also limits the size of networks that RIP can support. A hop countof 16 is considered an infinite distance and used to deprecate inaccessible, inoperable, or otherwiseundesirable routes in the selection process.
  10. 10. RIP implements the split horizon, route poisoning and holddown mechanisms to prevent incorrectrouting information from being propagated. These are some of the stability features of RIP. It is also [1]possible to use the so called RMTI (Routing Information Protocol with Metric-based Topology Investigation) algorithm to cope with the count-to-infinity problem. With its help, it ispossible to detect every possible loop with a very small computation effort.Limitations Without using RMTI, Hop count can not exceed 15, in the case that it exceeds this limitation, it will be considered invalid. Most RIP networks are flat. There is no concept of areas or boundaries in RIP networks. Variable Length Subnet Masks were not supported by RIP version 1. Without using RMTI, RIP has slow convergence and count to infinity problemsVirtual private networkA virtual private network (VPN) is a network that uses primarily public telecommunicationinfrastructure, such as the Internet, to provide remote offices or traveling users access to a centralorganizational network.VPNs typically require remote users of the network to be authenticated, and often secure data withencryption technologies to prevent disclosure of private information to unauthorized parties.VPNs may serve any network functionality that is found on any network, such as sharing of data andaccess to network resources, printers, databases, websites, etc. A VPN user typically experiences thecentral network in a manner that is identical to being connected directly to the central network. VPNtechnology via the public Internet has replaced the need to requisition and maintain expensivededicated leased-line telecommunication circuits once typical in wide-area network installations.(Desktop Management Interface) The first desktop management standard from the DMTF. Enabling PCs to bemonitored from a central console, it was superseded by the DMTFs Common Information Model (see CIM).The Management Information File (MIF)When a query is made to a DMI-enabled device, the memory-resident DMI agent sends back data such as modelID, serial number, memory and port addresses in a management information file (MIF). It can also extract datafrom memory to provide a current status.
  11. 11. Support for SNMPDMI can co-exist with SNMP. A single machine can serve as a proxy agent to service an entire LAN segment ofDMI machines. When SNMP queries arrive, it can transfer the data from the MIF into the SNMPs MIB(management information base). See CIM, SNMP, WBEM and DMTF.What is the Cisco Discovery Protocol (CDP)?CDP is a Cisco proprietary protocol that runs on all Cisco IOS-enabled devices. It is used to gatherinformation about directly connected neighboring devices. CDP operates at Layer 2 of the OSI modeland is media-independent. With CDP, you can tell the hardware type, device identifier, address list,software version, and active interfaces on neighboring Cisco devices. CDP is enabled by default onall Cisco equipment. It uses a nonroutable SNAP frame to communicate between devices.Note: Because CDP is media-independent it can operate over most media types. The only mediatypes CDP cannot operate over are X.25, because it doesnt support SNAP encapsulation, and FrameRelay point-to-multipoint interfaces.What are three reasons to disable CDP?Three reasons to disable CDP are as follows:. To save network bandwidth by not exchanging CDP frames.
  12. 12. . If you are connecting to non-Cisco devices.. Security. CDP broadcasts information about the device every 60 seconds. Sniffers and other devicescan view these broadcasts to discover information about your network.How do you disable CDP on Cisco routers?Two commands disable CDP on a Cisco router. To disable CDP on the entire device, use the no cdprun global command:RouterB(config)#no cdp runTo disable CDP on an interface only, use the no cdp enable interface command:RouterB(config)#int e0RouterB(config-if)#no cdp enableThis disables CDP on Ethernet interface 0.What does the show CDP command display?The show CDP command displays global CDP information about the device. It tells you when thedevice will send CDP packets and the CDP holdtime:RouterB#show cdpGlobal CDP information:Sending CDP packets every 60 secondsSending a holdtime value of 180 secondsNote: For the CCNA test, remember that the default time a device will send out CDP information is 60seconds and the default holdtime is 180 seconds.On a Cisco router, what does the show cdp neighbors command display?
  13. 13. The show cdp neighbors command displays the following:· Device ID (name of the device)· The local interface (local outgoing port)· The holdtime displayed in seconds· The devices capability code (this tells you if the device is a router, switch, or repeater)· Hardware platform of the neighboring device (what type of Cisco device it is and the model)· Port ID of the neighboring device (remote port)RouterB#show cdp neighborsCapability Codes:R - Router, T - Trans Bridge, B - Source Route BridgeS - Switch, H - Host, I - IGMP, r - RepeaterDevice ID Local Intrfce Holdtme Capability Platform Port IDRouterA Ser 0 146 R 2505 Ser 0What does the show cdp neighbors detail command display?The show cdp neighbors detail and show cdp entry * commands show the same output. They bothdisplay the following:· Device ID (host name) of the remote neighbor· Layer 3 address of the remote device (if the device has more than one Layer 3 address on itsinterface, only the primary address is shown)
  14. 14. · Device platform and capabilities· Local interface and outgoing port ID· Remote device holdtime in seconds· IOS type and versionRouterB#show cdp neighbors detail-------------------------Device ID: RouterAEntry address(es):IP address: 192.168.2.1Platform: cisco 2505, Capabilities: RouterInterface: Serial1, Port ID (outgoing port): Serial1Holdtime : 164 sec Version :Cisco Internetwork Operating System SoftwareIOS (tm) 2500 Software (C2500-D-L), Version 12.0(13), RELEASE SOFTWARE(fc1)Copyright (c) 1986-2000 by cisco Systems, Inc.Compiled Wed 06-Sep-00 01:08 by LindaWhat does the show cdp traffic command display?The show cdp traffic command displays information about interface traffic. This includes the numberof CDP packets sent and received and CDP errors:RouterB#show cdp trafficCDP counters :Packets output: 105, Input: 103
  15. 15. Hdr syntax: 0, Chksum error: 0, Encaps failed:No memory: 0, Invalid packet: 0, Fragmented: 0What does the show cdp interface command display?The show cdp interface command displays the status of CDP on all interfaces on your device:RouterB#show cdp interfaceEthernet0 is up, line protocol is downEncapsulation ARPASending CDP packets every 60 seconds Holdtime is 180 secondsSerial0 is up, line protocol is upEncapsulation HDLCSending CDP packets every 60 seconds Holdtime is 180 secondsSerial1 is up, line protocol is upEncapsulation HDLCSending CDP packets every 60 seconds Holdtime is 180 secondsWhat Cisco IOS router command can you use to see a neighbor routers IP address?To see a neighbor routers IP address, you must use the show cdp neighbor detail or show cdp entry *user mode or EXEC command. (This one will probably be on the exam)What IOS command do you use to view the active outbound telnet sessions for the current user on aCisco router?
  16. 16. The show sessions command displays the active outbound telnet sessions from that particular useron your router.RouterA#show sessionsConn Host Address Byte Idle Conn Name* 1 192.168.1.2 192.168.1.2 0 0 192.168.1.2What key sequence do you use to suspend a Telnet session on a remote system and return to yourlocal router?To suspend a Telnet session, press Ctrl-Shift-6, and then press X.How do you end a remote Telnet session on a Cisco router?To end a Telnet session, use the exit or logout command while youre on the remote device:RouterB>exit[Connection to 192.168.1.2 closed by foreign host]RouterA#Upon using the ping EXEC command, you receive one of the following responses:·.·!·?·C·U
  17. 17. ·IWhat does each of these responses mean?. = Each period indicates that the network server timed out while waiting for a reply.! =Each exclamation point indicates the receipt of a reply.? =Unknown packet type.C =A congestion experienced packet was received.U =A destination unreachable error PDU was received.I = The user interrupted the test.What is the trace EXEC command used for?RouterA#trace 192.168.2.2Type escape sequence to abort.Tracing the route to 192.168.2.21 192.168.2.2 16 msec 16 msec *Note: If trace responds with a * it means the probe timed out. If it responds with a ? it means itreceived an unknown packet type.What are the two ways in which a Cisco router resolves host names to IP addresses?A Cisco router resolves host names using either a host table on each router or a DNS server.What is the main purpose of RAM on a Cisco router?On most Cisco routers, the IOS is loaded into RAM, as well as the running configuration. It is alsoused to hold routing tables and packet buffers.
  18. 18. What is the function of ROM on a Cisco router?On a Cisco router, ROM is used to start and maintain the router.What is Flash memory used for on a Cisco router?Flash memory is used to store the Cisco IOS software image and, if there is room, multipleconfiguration files or multiple IOS files. On some routers (the 2500 series), it is also used to run theIOS.What is the function of NVRAM on a Cisco router?Nonvolatile Random-Access Memory (NVRAM) is used to hold the saved router configuration. Thisconfiguration is not lost when the router is turned off or reloaded.What is the main purpose of the configuration register on a Cisco router?The configuration registers main purpose is to control how the router boots up. It is a 16-bit softwareregister that by default is set to load the Cisco IOS from Flash memory and to look for and load thestartup-config file from NVRAM.What Cisco IOS command would you use to view the current configuration register value?The show version command is used to display the routers current configuration register:RouterA#show versionCisco Internetwork Operating System SoftwareIOS (tm) 2500 Software (C2500-D-L),Version 12.0(13), RELEASE SOFTWARE (fc1)Copyright (c) 1986-2000 by cisco Systems,Inc.Compiled Wed 06-Sep-00 01:08 by lindaImage text-base: 0x030388F8, data-base: 0x00001000Configuration register is 0x2102How do you change the configuration register on a Cisco router?To change the configuration register on a Cisco router, use the config-register global command.
  19. 19. What Cisco IOS command displays the contents of Flash memory?The show flash command displays the contents of Flash memory. This includes the images stored inFlash memory, the images names, bytes used in Flash memory, bytes available, and the totalamount of Flash memory on your router:RouterA#show flashSystem flash directory:File Length Name/status1 6897716 c2500-d-l.120-13.bin[6897780 bytes used, 1490828 available, 8388608 total]8192K bytesof processor board System flash (Read ONLY)What IOS command would you use to copy the running configuration on a router to a TFTP server?To copy the running configuration to a TFTP server, use the copy running-config tftp privileged EXECcommand:RouterB#copy run tftpAddress or name of remote host []? 192.168.0.2Destination filename [routerb-confg]?!!780 bytes copied in 6.900 secs (130 bytes/sec)This gives you a backup of your running config on a TFTP server.How do you erase the routers configuration and bring it back to the factory default?The erase startup-config privileged EXEC command erases your routers configuration, thus bringingit back to its factory defaults:RouterB#erase startup-config
  20. 20. Erasing the nvram filesystem will remove all files! Continue? [confirm][OK]Erase of nvram: completeNote: In order to complete the process, you need to reload the router. An older IOS command thatyou can use to accomplish the same results is write erase.How do you restore a configuration file from a TFTP server into your Cisco routers RAM?The copy tftp running-config privileged EXEC command merges the saved and running configurationinto your routers RAM, so any commands not explicitly change or removed will remain in the runningconfiguration.RouterB#copy tftp running-configAddress or name of remote host []? 192.168.0.2Source filename []? routerb-confgDestination filename [running-config]?Accessing tftp://192.168.0.2/routerb-confg...Loading routerb-confg from 192.168.0.2 (via Ethernet0):![OK - 780/1024 bytes] 780 bytes copied in 4.12 secs (195 bytes/sec)RouterB# 01:40:46: %SYS-5-CONFIG: Configured from tftp://192.168.0.2/routerb-confgHow do you back up a Cisco router IOS?To back up the current IOS image on your router, use the copy flash tftp privileged EXEC modecommand:RouterB#copy flash tftp
  21. 21. Source filename [routerb-flash]? flash:c2500-d-l.120-13.binAddress or name of remote host []? 192.168.0.2Destination filename [c2500-d-l.120-13.bin]?!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!6897716 bytes copied in 90.856 secs(76641 bytes/sec)How do you upgrade or restore the Cisco router IOS?To upgrade or restore the Cisco router IOS, use the copy tftp flash privileged EXEC mode command.How you make a Cisco router a TFTP server?To configure a Cisco router as a TFTP server, use the tftp-server global configuration command.What is the boot sequence of a Cisco router?The boot sequence of a router is as follows:hardware /power onload run bootstrapfind the IOS softwareload the softwarefind the config (default NVRAM)load the configuration (startup-config) into RAMRun the IOSWhat can you configure on a router in setup mode?ip addresses
  22. 22. routed protocolsenable passwordImportant Config Register Notes:2100 manual boot rommon>2101 boot from ROM2102 normal/password recovery2105 boot system command - config-register NVRAM2142 bypass NVRAMctrl-break = ROM monitor moderouter(config)#boot system flash ios filenamerouter(config)#boot system tftp filename ip addressrouter(config)#boot system ROMNote the router prompt for boot commands. Copy commands = router#

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