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CCNA - Cisco


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CCNA - Cisco

  1. 1. Mohannad Al-Hanahnah© 2003, Cisco Systems, Inc. All rights reserved.
  2. 2. Communications and Services Certifications Mohannad Al-Hanahnah
  3. 3. Mohannad Al-Hanahnah
  4. 4. Data NetworksSharing data through the use of floppy disks is not an efficient orcost-effective manner in which to operate businesses.Businesses needed a solution that would successfully address thefollowing three problems:• How to avoid duplication of equipment and resources• How to communicate efficiently• How to set up and manage a networkBusinesses realized that networking technology could increaseproductivity while saving money. Mohannad Al-Hanahnah
  5. 5. Networking DevicesEquipment that connects directly to a network segment is referredto as a device.These devices are broken up into two classifications.• end-user devices• network devicesEnd-user devices include computers, printers, scanners, and otherdevices that provide services directly to the user.Network devices include all the devices that connect the end-userdevices together to allow them to communicate. Mohannad Al-Hanahnah
  6. 6. Network Interface CardA network interface card (NIC) is a printed circuit board thatprovides network communication capabilities to and from apersonal computer. Also called a LAN adapter. Mohannad Al-Hanahnah
  7. 7. Networking Device Icons Mohannad Al-Hanahnah
  8. 8. Cisco Icons and Symbols Router Wireless Secure Router Firewall Home Office RouterWorkgroup Access Point IP Phone Mobile Small Switch Access Business Phone Wireless Line: Serial Line: Ethernet Connectivity Mohannad Al-Hanahnah
  9. 9. RepeaterA repeater is a network device used to regenerate a signal.Repeaters regenerate analog or digital signals distorted bytransmission loss due to attenuation. A repeater does not performintelligent routing. Mohannad Al-Hanahnah
  10. 10. HubHubs concentrate connections.In other words, they take agroup of hosts and allow thenetwork to see them as a singleunit.This is done passively, withoutany other effect on the datatransmission.Active hubs not onlyconcentrate hosts, but theyalso regenerate signals. Mohannad Al-Hanahnah
  11. 11. BridgeBridges convert network transmission data formats as well asperform basic data transmission management. Bridges, as thename implies, provide connections between LANs. Not only dobridges connect LANs, but they also perform a check on the data todetermine whether it should cross the bridge or not. This makeseach part of the network more efficient. Mohannad Al-Hanahnah
  12. 12. Workgroup SwitchWorkgroup switches add moreintelligence to data transfermanagement.Switches can determinewhether data should remainon a LAN or not, and they cantransfer the data to theconnection that needs thatdata. Mohannad Al-Hanahnah
  13. 13. RouterRouters have all capabilities of the previous devices. Routers canregenerate signals, concentrate multiple connections, convert datatransmission formats, and manage data transfers.They can alsoconnect to a WAN, which allows them to connect LANs that areseparated by great distances. Mohannad Al-Hanahnah
  14. 14. “The Cloud”The cloud is used in diagrams to represent where the connection tothe internet is.It also represents all of the devices on the internet. Mohannad Al-Hanahnah
  15. 15. Network TopologiesNetwork topology defines the structure of the network.One part of the topology definition is the physical topology, which isthe actual layout of the wire or media.The other part is the logical topology,which defines how the mediais accessed by the hosts for sending data. Mohannad Al-Hanahnah
  16. 16. Physical Topologies Mohannad Al-Hanahnah
  17. 17. Bus TopologyA bus topology uses a single backbone cable that is terminated atboth ends.All the hosts connect directly to this backbone. Mohannad Al-Hanahnah
  18. 18. Ring TopologyA ring topology connects one host to the next and the last host tothe first.This creates a physical ring of cable. Mohannad Al-Hanahnah
  19. 19. Star TopologyA star topology connects all cables to a central point ofconcentration. Mohannad Al-Hanahnah
  20. 20. Extended Star TopologyAn extended star topology links individual stars together byconnecting the hubs and/or switches.This topology can extend thescope and coverage of the network. Mohannad Al-Hanahnah
  21. 21. Hierarchical TopologyA hierarchical topology is similar to an extended star. Mohannad Al-Hanahnah
  22. 22. Mesh TopologyA mesh topology is implemented to provide as muchprotection as possible from interruption of service.Each host has its own connections to all other hosts. Althoughthe Internet has multiple paths to any one location, it doesnot adopt the full mesh topology. Mohannad Al-Hanahnah
  23. 23. LANs, MANs, & WANsOne early solution was the creation of local-area network (LAN)standards which provided an open set of guidelines for creatingnetwork hardware and software, making equipment from differentcompanies compatible.What was needed was a way for information to move efficiently andquickly, not only within a company, but also from one business toanother.The solution was the creation of metropolitan-area networks(MANs) and wide-area networks (WANs). Mohannad Al-Hanahnah
  24. 24. Examples of Data Networks Mohannad Al-Hanahnah
  25. 25. LANsMohannad Al-Hanahnah
  26. 26. Cellular Topology for Wireless Mohannad Al-Hanahnah
  27. 27. WANsMohannad Al-Hanahnah
  28. 28. SANsA SAN is a dedicated, high-performance network used tomove data between servers andstorage resources.Because it is a separate,dedicated network, it avoids anytraffic conflict between clientsand servers. Mohannad Al-Hanahnah
  29. 29. Virtual Private NetworkA VPN is a private network that is constructed within a public networkinfrastructure such as the global Internet. Using VPN, a telecommuter canaccess the network of the company headquarters through the Internet bybuilding a secure tunnel between the telecommuter’s PC and a VPN router inthe headquarters. Mohannad Al-Hanahnah
  30. 30. Bandwidth Mohannad Al-Hanahnah
  31. 31. Measuring Bandwidth Mohannad Al-Hanahnah
  32. 32. Mohannad Al-Hanahnah
  33. 33. Understanding Host-to-Host Communications– Older model • Proprietary • Application and combinations software controlled by one vendor– Standards-based model • Multivendor software • Layered approach Mohannad Al-Hanahnah
  34. 34. Why do we need the OSI Model?To address the problem of networks increasing in size andin number, the International Organization forStandardization (ISO) researched many network schemesand recognized that there was a need to create a networkmodel that would help network builders implementnetworks that could communicate and work together andtherefore, released the OSI reference model in 1984. Mohannad Al-Hanahnah
  35. 35. OSI Model Reduces complexity Standardizes interfaces Ensures interoperable technology Accelerates evolution Simplifies teaching and learning Mohannad Al-Hanahnah
  36. 36. Don’t Get Confused.ISO - International Organization for StandardizationOSI - Open System InterconnectionIOS - Internetwork Operating SystemThe ISO created the OSI to make the IOS more efficient.The “ISO” acronym is correct as shown.To avoid confusion, some people say “InternationalStandard Organization.” Mohannad Al-Hanahnah
  37. 37. The OSI Reference Model7 Application The OSI Model will be used throughout your entire6 Presentation networking career!5 Session4 Transport3 Network Memorize it!2 Data Link1 Physical Mohannad Al-Hanahnah
  38. 38. Layer 7 - The Application Layer7 Application This layer deal with networking applications.6 Presentation5 Session Examples:4 Transport  Email  Web browsers3 Network2 Data Link PDU - Data1 Physical Mohannad Al-Hanahnah
  39. 39. Layer 6 - The Presentation Layer7 Application This layer is responsible for presenting the data in the6 Presentation required format which may5 Session include:4 Transport  Encryption  Compression3 Network2 Data Link PDU - Data1 Physical Mohannad Al-Hanahnah
  40. 40. Layer 5 - The Session Layer7 Application This layer establishes, manages, and terminates sessions6 Presentation between two communicating5 Session hosts.4 Transport3 Network PDU - Data2 Data Link1 Physical Mohannad Al-Hanahnah
  41. 41. Layer 4 - The Transport Layer7 Application This layer breaks up the data from the sending host and then6 Presentation reassembles it in the receiver.5 Session4 Transport It also is used to insure reliable data transport across the3 Network network. Also provide error2 Data Link correction.1 Physical PDU - Segments Mohannad Al-Hanahnah
  42. 42. Layer 3 - The Network Layer7 Application Makes “Best Path6 Presentation Determination” decisions based5 Session on logical addresses (usually IP4 Transport addresses).3 Network PDU - Packets2 Data Link1 Physical Mohannad Al-Hanahnah
  43. 43. Layer 2 - The Data Link Layer7 Application This layer provides reliable transit of data across a physical6 Presentation link “error detection”.5 Session4 Transport Makes decisions based on physical addresses (usually MAC3 Network addresses).2 Data Link PDU - Frames1 Physical Mohannad Al-Hanahnah
  44. 44. Layer 1 - The Physical Layer This is the physical media7 Application through which the data,6 Presentation represented as electronic signals, is sent from the source host to5 Session the destination host.4 Transport3 Network PDU - Bits2 Data Link1 Physical Mohannad Al-Hanahnah
  45. 45. Host Layers7 Application These layers only exist in the source6 Presentation and destination5 Session host computers.4 Transport3 Network2 Data Link1 Physical Mohannad Al-Hanahnah
  46. 46. Media Layers7 Application6 Presentation5 Session4 Transport These layers manage the3 Network information out in the2 Data Link LAN or WAN between the1 Physical source and destination hosts. Mohannad Al-Hanahnah
  47. 47. Data Encapsulation Mohannad Al-Hanahnah
  48. 48. Data De-Encapsulation Mohannad Al-Hanahnah
  49. 49. Peer-to-Peer Communication Mohannad Al-Hanahnah
  50. 50. Data Flow Through a Network Mohannad Al-Hanahnah
  51. 51. Mohannad Al-Hanahnah
  52. 52. Cabling the Campus Core_ Server core_sw_a Leased Line/ISDN Cloud Frame Relay Mohannad Al-Hanahnah
  53. 53. Unshielded Twisted-Pair Cable– Speed and throughput: 10 to 1000 Mb/s– Average cost per node: Least expensive– Media and connector size: Small– Maximum cable length: Varies Mohannad Al-Hanahnah
  54. 54. RJ-45 Connector Mohannad Al-Hanahnah
  55. 55. RJ-45 Jack Mohannad Al-Hanahnah
  56. 56. UTP Implementation (Straight-Through) Cable 10BASE-T/ 100BASE-TX Straight-Through Straight-Through Cable Pin Label Pin Label 1 TX+ 1 TX+ 2 TX- 2 TX- 3 RX+ 3 RX+ 4 NC 4 NC 5 NC 5 NC 6 RX- 6 RX- 7 NC 7 NC Wires on cable ends 8 NC 8 NC are in same order. Mohannad Al-Hanahnah
  57. 57. UTP Implementation (Crossover) Cable 10BASE-T or100BASE-TX Straight-Through Crossover Cable EIA/TIA T568A EIA/TIA T568B Pin Label Pin Label 1 TX+ 1 TX+ 2 TX- 2 TX- 3 RX+ 3 RX+ 4 NC 4 NC 5 NC 5 NC 6 RX- 6 RX- 7 NC 7 NC Some wires on cable 8 NC 8 NC ends are crossed. Mohannad Al-Hanahnah
  58. 58. Ethernet StandardsThe Ethernet standard specifies that each of the pins on an RJ-45connector have a particular purpose. A NIC transmits signals onpins 1 & 2, and it receives signals on pins 3 & 6. Mohannad Al-Hanahnah
  59. 59. Remember…A straight cable has T568B or T568A on both ends. A crossover (or cross-connect) cable has T568B on one end and T568A on the other. A consolecable had T568B on one end and reverse T568B on the other, which iswhy it is also called a rollover cable. Mohannad Al-Hanahnah
  60. 60. UTP Implementation: Straight-Through vs. Crossover Mohannad Al-Hanahnah
  61. 61. Using Varieties of UTP Mohannad Al-Hanahnah
  62. 62. Shielded Twisted Pair (STP) Cable Mohannad Al-Hanahnah
  63. 63. Coaxial Cable Mohannad Al-Hanahnah
  64. 64. Fiber Optic Cable Mohannad Al-Hanahnah
  65. 65. Fiber Optic ConnectorsConnectors are attached to the fiber ends so that the fibers can beconnected to the ports on the transmitter and receiver.The type of connector most commonly used with multimode fiber isthe Subscriber Connector (SC connector).On single-mode fiber, theStraight Tip (ST) connector is frequently used Mohannad Al-Hanahnah
  66. 66. Cable Specifications10BASE-TThe T stands for twisted pair.10BASE5The 5 represents the fact that a signal can travel for approximately 500meters 10BASE5 is often referred to as Thicknet.10BASE2The 2 represents the fact that a signal can travel for approximately 200meters 10BASE2 is often referred to as Thinnet.All 3 of these specifications refer to the speed of transmission at 10 Mbpsand a type of transmission that is baseband, or digitally interpreted. Thinnetand Thicknet are actually a type of networks, while 10BASE2 & 10BASE5 arethe types of cabling used in these networks. Mohannad Al-Hanahnah
  67. 67. Comparing Ethernet Media Requirements Mohannad Al-Hanahnah
  68. 68. LAN Physical Layer Implementation Mohannad Al-Hanahnah
  69. 69. WAN Physical Layer Implementations • Physical layer implementations vary • Cable specifications define speed of link Frame HDLC PPP Relay ISDN BRI (with PPP) EIA/TIA-232 RJ-45 EIA/TIA-449 X.21 V.24 V.35 HSSI Mohannad Al-Hanahnah
  70. 70. Serial Point-to-Point Connections Mohannad Al-Hanahnah
  71. 71. Serial Implementation of DTE & DCEWhen connecting directly to a service provider, or to a devicesuch as a CSU/DSU that will perform signal clocking, the router isa DTE and needs a DTE serial cable.This is typically the case for routers. Mohannad Al-Hanahnah
  72. 72. Back-to-Back Serial ConnectionWhen performinga back-to-backrouter scenario ina testenvironment, oneof the routers willbe a DTE and theother will be aDCE. Mohannad Al-Hanahnah
  73. 73. RepeaterA repeater is a network device used to regenerate a signal.Repeaters regenerate analog or digital signals distorted bytransmission loss due to attenuation.Repeater is a Physical Layerdevice Mohannad Al-Hanahnah
  74. 74. The 4 Repeater RuleThe Four Repeater Rule for 10-Mbps Ethernet should be used as astandard when extending LAN segments.This rule states that no more than four repeaters can beused between hosts on a LAN. Mohannad Al-Hanahnah
  75. 75. HubHubs concentrateconnections.In other words,they take a group of hosts andallow the network to see themas a single unit.Hub is a physical layer device. All devices in the same collision domain. All devices in the same broadcast domain. Devices share the same bandwidth. Mohannad Al-Hanahnah
  76. 76. Network Interface CardThe function of a NIC is to connect a host device to the network medium.A NIC is a printed circuit board that fits into the expansion slot on the motherboard orperipheral device of a computer. The NIC is also referred to as a network adapter.NICs are considered Data Link Layer devices because each NIC carries a unique code called aMAC address. Mohannad Al-Hanahnah
  77. 77. MAC AddressMAC address is 48 bits in length and expressed as twelve hexadecimaldigits.MAC addresses are sometimes referred to as burned-in addresses (BIA)because they are burned into read-only memory (ROM) Mohannad Al-Hanahnah
  78. 78. BridgeBridges are Data Link layer devices.Connected hostaddresses are learned and stored on a MAC addresstable.Each bridge port has a unique MAC address Mohannad Al-Hanahnah
  79. 79. BridgesMohannad Al-Hanahnah
  80. 80. Bridging Graphic Mohannad Al-Hanahnah
  81. 81. SwitchSwitches are Data Link layerdevices.Each Switch port has a uniqueMAC address.Connected host MACaddresses are learned andstored on a MAC addresstable. Mohannad Al-Hanahnah
  82. 82. • No. of broadcast domain=No. of router interfaces• Switches create separate collision domains but a single broadcast domain.Routers provide a separate broadcast domain for each interface. Mohannad Al-Hanahnah
  83. 83. Hub: One collision domain, one broadcast domainBridge: Two collision domains, one broadcast domainSwitch: Four collision domains, one broadcast domainRouter: Three collision domains, three broadcast domains Mohannad Al-Hanahnah
  84. 84. Switching Modescut-throughA switch starts to transfer the frame as soon as the destination MAC address isreceived. No error checking is switch can receive the entire frame before sending it out the destinationport. This gives the switch software an opportunity to verify the Frame CheckSum (FCS) to ensure that the frame was reliably received before sending it to thedestination.fragment-freeA compromise between the cut-through and store-and-forward modes.Fragment-free reads the first 64 bytes, which includes the frame header, andswitching begins before the entire data field and checksum are read. Mohannad Al-Hanahnah
  85. 85. Full DuplexAnother capability emerges when only two nodes are connected. In a network that usestwisted-pair cabling, one pair is used to carry the transmitted signal from one node to theother node. A separate pair is used for the return or received signal. It is possible for signalsto pass through both pairs simultaneously. The capability of communication in bothdirections at once is known as full duplex. Mohannad Al-Hanahnah
  86. 86. Switches – MAC Tables Mohannad Al-Hanahnah
  87. 87. Peer-to-Peer NetworkIn a peer-to-peer network, networked computers act as equal partners, or peers.As peers, each computer can take on the client function or the server function.At one time, computer A may make a request for a file from computer B, which respondsby serving the file to computer A. Computer A functions as client, while B functions as theserver. At a later time, computers A and B can reverse roles.In a peer-to-peer network, individual users control their own resources. Peer-to-peernetworks are relatively easy to install and operate. As networks grow, peer-to-peerrelationships become increasingly difficult to coordinate. Mohannad Al-Hanahnah
  88. 88. Client/Server NetworkIn a client/server arrangement, network services are located on a dedicated computercalled a server.The server responds to the requests of clients.The server is a central computer that is continuously available to respond to requests fromclients for file, print, application, and other services.Most network operating systems adopt the form of a client/server relationship. Mohannad Al-Hanahnah
  89. 89. Mohannad Al-Hanahnah
  90. 90. Why Another Model?Although the OSI reference model is universallyrecognized, the historical and technical open standardof the Internet is Transmission Control Protocol /Internet Protocol (TCP/IP).The TCP/IP reference model and the TCP/IP protocolstack make data communication possible between anytwo computers, anywhere in the world, at nearly thespeed of light.The U.S. Department of Defense (DoD) created theTCP/IP reference model. Mohannad Al-Hanahnah
  91. 91. Don’t Confuse the Models7 Application6 Presentation Application5 Session4 Transport Transport3 Network Internet2 Data Link Network1 Physical Access Mohannad Al-Hanahnah
  92. 92. 2 Models Side-By-Side7 Application6 Presentation Application5 Session4 Transport Transport3 Network Internet2 Data Link Network1 Physical Access Mohannad Al-Hanahnah
  93. 93. The Application LayerThe applicationlayer of theTCP/IP modelhandles high-level protocols,issues ofrepresentation,encoding, anddialog control. Mohannad Al-Hanahnah
  94. 94. The Transport LayerThe transport layer provides transport services fromthe source host to the destination host. It constitutesa logical connection between these endpoints of thenetwork. Transport protocols segment andreassemble upper-layer applications into the samedata stream between endpoints. Mohannad Al-Hanahnah
  95. 95. The Internet Layer The purpose of the Internet layer is to select the best path through the network for packets to travel. The main protocol that functions at this layer is the Internet Protocol (IP). Best path determination and packet switching occur at this layer. Mohannad Al-Hanahnah
  96. 96. The Network Access Layer It the layer that is concerned with all of the issues that an IP packet requires to actually make a physical link to the network media. It includes LAN and WAN details, and all the details contained in the OSI physical and data-link layers. NOTE: ARP & RARP work at both the Internet and Network Access Layers. Mohannad Al-Hanahnah
  97. 97. Introduction to the Transport LayerThe primary duties of the transport layer, Layer 4 of the OSImodel, are to transport and regulate the flow of information fromthe source to the destination, reliably and accurately.End-to-end control and reliability are provided by slidingwindows, sequencing numbers, and acknowledgments. Mohannad Al-Hanahnah
  98. 98. More on The Transport LayerThe transport layer provides transport services from thesource host to the destination host.It establishes a logical connection between the endpoints ofthe network.Transport services include the following basic services:• Segmentation of upper-layer application data• Transport of segments from one end host to another end host• Flow control provided by sliding windows• Reliability provided by sequence numbers and acknowledgments Mohannad Al-Hanahnah
  99. 99. Flow ControlAs the transport layer sends data segments, it tries to ensure that data is not lost.A receiving host that is unable to process data as quickly as it arrives could be acause of data loss.Flow control avoids the problem of a transmitting host overflowing the buffers inthe receiving host. Mohannad Al-Hanahnah
  100. 100. TCPTransmission Control Protocol (TCP) is a connection-oriented Layer 4protocol that provides reliable full-duplex data transmission.TCP is part of the TCP/IP protocol stack. In a connection-orientedenvironment, a connection is established between both ends before thetransfer of information can begin.TCP is responsible for breaking messages into segments, reassemblingthem at the destination station, resending anything that is not received,and reassembling messages from the segments.TCP supplies a virtualcircuit between end-user applications.The protocols that use TCP include:• FTP (File Transfer Protocol)• HTTP (Hypertext Transfer Protocol)• SMTP (Simple Mail Transfer Protocol)• Telnet Mohannad Al-Hanahnah
  101. 101. TCP Segment Format Mohannad Al-Hanahnah
  102. 102. UDPUser Datagram Protocol (UDP) is the connectionless transport protocolin the TCP/IP protocol stack.UDP is a simple protocol that exchanges datagrams, withoutacknowledgments or guaranteed delivery. Error processing andretransmission must be handled by higher layer protocols.UDP uses no windowing or acknowledgments so reliability, if needed, isprovided by application layer protocols. UDP is designed for applicationsthat do not need to put sequences of segments together.The protocols that use UDP include:• TFTP (Trivial File Transfer Protocol)• SNMP (Simple Network Management Protocol)• DHCP (Dynamic Host Control Protocol)• DNS (Domain Name System) Mohannad Al-Hanahnah
  103. 103. UDP Segment Format Mohannad Al-Hanahnah
  104. 104. Well Known Port NumbersThe following port numbers should be memorized:NOTE:The curriculum forgot to mention one of the most important port numbers.Port 80 is used for HTTP or WWW protocols. (Essentially access to the internet.) Mohannad Al-Hanahnah
  105. 105. 3-Way HandshakeTCP requires connection establishment before data transfer begins.For a connection to be established or initialized, the two hosts mustsynchronize their Initial Sequence Numbers (ISNs). CTL = Which control bits in the TCP header Mohannad Al-Hanahnah
  106. 106. Basic WindowingData packets must bedelivered to therecipient in the sameorder in which theywere transmitted tohave a reliable,connection-orienteddata transfer.The protocol fails ifany data packets arelost, damaged,duplicated, orreceived in a differentorder.An easy solution is tohave a recipientacknowledge thereceipt of each packetbefore the nextpacket is sent. Mohannad Al-Hanahnah
  107. 107. Sliding Window Mohannad Al-Hanahnah
  108. 108. TCP Sequence & Acknowledgement Mohannad Al-Hanahnah
  109. 109. Mohannad Al-Hanahnah
  110. 110. Decimal vs. Binary Numbers– Decimal numbers are represented by the numbers 0 through 9.– Binary numbers are represented by a series of 1s and 0s. Mohannad Al-Hanahnah
  111. 111. Decimal and Binary Numbers ChartBase-10 Decimal Conversion—63204829 MSB LSB Baseexponent 107 106 105 104 103 102 101 100 Column Value 6 3 2 0 4 8 2 9 Decimal Weight 10000000 1000000 100000 10000 1000 100 10 1 Column Weight 60000000 3000000 200000 0 4000 800 20 9 60000000 + 3000000 + 200000 + 0 + 4000 + 800 + 20 + 9 = 63204829Base-2 Binary Conversion—11101001 (233) MSB LSB Baseexponent 27 26 25 24 23 22 21 20 Column Value 1 1 1 0 1 0 0 1 Decimal Weight 128 64 32 16 8 4 2 1 Column Value 128 64 32 0 8 0 0 1 128 + 64 + 32 + 0 + 8 + 0 + 0 + 1 = 233
  112. 112. Powers of 2 Mohannad Al-Hanahnah
  113. 113. Decimal-to-Binary Conversion 35 = 25 + 21 + 20 35 = (32 * 1) + (2 * 1) + (1 * 1) 35 = 0 + 0 + 1 + 0 + 0 + 0 +1 + 1 35 = 00100011 Mohannad Al-Hanahnah
  114. 114. Binary-to-Decimal Conversion1 0 1 1 1 0 0 1 = (128 * 1) + (64 * 0) + (32 * 1) + (16 * 1) + (8 * 1) + (4 * 0) + (2 * 0) + (1 * 1)1 0 1 1 1 0 0 1 = 128 + 0 + 32 + 16 + 8 + 0 + 0 + 11 0 1 1 1 0 0 1 = 185 Mohannad Al-Hanahnah
  115. 115. Mohannad Al-Hanahnah
  116. 116. Why IP Addresses?– They uniquely identify each device on an IP network.– Every host (computer, networking device, peripheral) must have a unique address.
  117. 117. Network Layer Communication PathA router forwards packets from the originating network to thedestination network using the IP protocol. The packets mustinclude an identifier for both the source and destination networks. Mohannad Al-Hanahnah
  118. 118. Network PDU Header Mohannad Al-Hanahnah
  119. 119. Network and Host DivisionEach complete 32-bit IP address is broken down into a network partand a host part. A bit or bit sequence at the start of each addressdetermines the class of the address. There are 5 IP address classes. Mohannad Al-Hanahnah
  120. 120. IP Address Format: Dotted Decimal Notation Mohannad Al-Hanahnah
  121. 121. IP Address RangesThe graphic below shows the IP address range of the first octetboth in decimal and binary for each IP address class. Mohannad Al-Hanahnah
  122. 122. IP Address Classes: The First Octet Mohannad Al-Hanahnah
  123. 123. IP Address Ranges*127 (01111111) is a Class A address reserved for loopback testing andcannot be assigned to a network. Mohannad Al-Hanahnah
  124. 124. Reserved Address Mohannad Al-Hanahnah
  125. 125. Public IP AddressesUnique addresses are required for each device on a network.The Internet Assigned Numbers Authority (IANA).No two machines that connect to a public network can have the same IPaddress because public IP addresses are global and standardized.All machines connected to the Internet agree to conform to the system.Public IP addresses must be obtained from an Internet service provider(ISP) or a registry at some expense. Mohannad Al-Hanahnah
  126. 126. Private IP AddressesPrivate IP addresses are another solution to the problem of theimpending exhaustion of public IP addresses.As mentioned, publicnetworks require hosts to have unique IP addresses.However, private networks that are not connected to the Internet mayuse any host addresses, as long as each host within the privatenetwork is unique. Class Private Address Range A to B to C to 192.168.255 Mohannad Al-Hanahnah
  127. 127. Network Address Mohannad Al-Hanahnah
  128. 128. Broadcast Address Mohannad Al-Hanahnah
  129. 129. Network/Broadcast Addresses at the Binary LevelAn IP address that has binary 0s in all host bit positions isreserved for the network address, which identifies the network.An IP address that has binary 1s in all host bit positions isreserved for the broadcast address, which is used to send datato all hosts on the network. Here are some examples:Class Network Address Broadcast AddressA Al-Hanahnah
  130. 130. DHCPMohannad Al-Hanahnah
  131. 131. Network Connection Mohannad Al-Hanahnah
  132. 132. ipconfigMohannad Al-Hanahnah
  133. 133. HOW WILL YOU FIND How many bits are NETWORK portion ? How many bits are HOST portion ? Solution : Using Network Prefix or Subnet Mask . . . Mohannad Al-Hanahnah
  134. 134. Subnet maskSubnet Mask is another common method used to identify the network portion and host portion of an IP address.In a subnet mask, All network bits = 1 All host bits = 0For example, subnet mask = Mohannad Al-Hanahnah
  135. 135. Default Subnet masks of IPv4 Classes Mohannad Al-Hanahnah
  136. 136. Network PrefixesA Network Prefix is a method to identify the network portion and host portion of an IP address.The prefix length is nothing but the number of network bits in the IP address.For example, in /24, the number 24 is no. of network bits.the subnet mask = Mohannad Al-Hanahnah
  137. 137. How to find the Network address when a Host IP and Subnet mask is given …Any IPv4 Networkaddress Address Mohannad Al-Hanahnah
  138. 138. AND ing the Host IP and Subnet mask to get Network Address 0 Mohannad Al-Hanahnah
  139. 139. Mohannad Al-Hanahnah
  140. 140. Introduction to SubnettingSubnetting a network means to use the subnet mask to divide thenetwork and break a large network up into smaller, more efficient andmanageable segments, or subnets.With subnetting, the network is not limited to the default Class A, B, orC network masks and there is more flexibility in the network design.Subnet addresses include the network portion, plus a subnet field anda host field.The ability to decide how to divide the original host portioninto the new subnet and host fields provides addressing flexibility forthe network administrator. Mohannad Al-Hanahnah
  141. 141. Subnetting Review• To identify subnets, you will “borrow” bits from the host ID portion of the IP address: – The number of subnets available depends on the number of bits borrowed. • The available number of subnets = 2s, I which s is the number of bits borrowed. – The number of hosts per subnet available depends upon the number of host ID bits not borrowed. • The available number of hosts per subnet = 2h -2, in which h is the number of host bits not borrowed. • One address is reserved as the network address. • One address is reserved as the broadcast address. Mohannad Al-Hanahnah
  142. 142. Possible Subnets and Hosts for a Class C Network Mohannad Al-Hanahnah
  143. 143. Possible Subnets and Hosts for a Class B Network Mohannad Al-Hanahnah
  144. 144. Possible Subnets and Hosts for a Class A Network Mohannad Al-Hanahnah
  145. 145. To create a subnet follow these steps:1.Determine the number of required network IDs:One for each subnet2.Determine the number of required host IDs per subnet:One for each hostOne for each router interface3.Based on the above requirements, create the following:One subnet mask for your entire networkA unique subnet ID for each physical segmentA range of host IDs for each subnet Mohannad Al-Hanahnah
  146. 146. In a Class C address, only 8 bits are available for defining the hosts. Rememberthat subnet bits start at the left and go to the right, without skipping bits. Thismeans that the only Class C subnet masks can be the following:We can’t use a /31 or /32 because we have to have at least 2 host bits forassigning IP addresses to hosts. Mohannad Al-Hanahnah
  147. 147. When you’ve chosen a possible subnet mask for your network and need todetermine the number of subnets, valid hosts, and broadcast addresses ofa subnet that the mask provides, all you need to do is answer five simplequestions:• How many subnets does the chosen subnet mask produce?• How many valid hosts per subnet are available?• What are the valid subnets?• What’s the broadcast address of each subnet?• What are the valid hosts in each subnet?How many subnets? 2s, I which s is the number of bits borrowed. For example,in 11000000, the number of 1s gives us 22 subnets. In this example, thereare 4 subnets.How many hosts per subnet? 2h -2, in which h is the number of host bits notborrowed. For example, in 11000000, the number of 0s gives us 26 – 2hosts. In this example, there are 62 hosts per subnet. You need to subtract 2 forthe subnet address and the broadcast address, which are not valid hosts. Mohannad Al-Hanahnah
  148. 148. What are the valid subnets? 256 – subnet mask = block size, or incrementnumber. An example would be 256 – 192 = 64. The block size of a 192 mask isalways 64. Start counting at zero in blocks of 64 until you reach the subnet maskvalue and these are your subnets. 0, 64, 128, 192.What’s the broadcast address for each subnet? Since we counted our subnets inthe last section as 0, 64, 128, and 192, the broadcast address is always thenumber right before the next subnet. For example, the 0 subnet has a broadcastaddress of 63 because the next subnet is 64. The 64 subnet has a broadcastaddress of 127 because the next subnet is 128. And so on.What are the valid hosts? Valid hosts are the numbers between the subnets,omitting the all 0s and all 1s. For example, if 64 is the subnet number and 127 isthe broadcast address, then 65–126 is the valid host range —it’s always thenumbers between the subnet address and the broadcast address. Mohannad Al-Hanahnah
  149. 149. Calculate all things??? 00100001Number of network=16 {0,16,32,48,64,80,96,112,128,144,160 176,192,208,224,240}Number of hosts=16-2=14block size=16Network ID :: usable :: usable :: address:: Mohannad Al-Hanahnah
  150. 150. ( Calculate all things? 01000001number of network=4 {0,64,128,192}number of hosts =64-2=62Network ID :: usable :: usable :: address:: Mohannad Al-Hanahnah
  151. 151. = Network address255.255.192.0 = Subnet maskCalculate every things??Number Subnets? 22 = 4Number Hosts? 214 – 2 = 16,382Valid subnets? 256 – 192= 64 {0, 64, 128, 192} Mohannad Al-Hanahnah
  152. 152. = Network address255.255.240.0 = Subnet maskCalculate all things??Number Subnets? 24 = 16Number Hosts? 212 – 2 = 4094Valid subnets? 256 – 240= 16 {0, 16, 32, 48, etc., up to 240} Mohannad Al-Hanahnah
  153. 153. Given the Class C network of, subnet the network in order to createthe network in Figure with the host requirements shown.? You need three subnet bits>>> 23 =8 subnetwork Number of host >>>> 25 -2=32-2=30 hosts Subnetmask >>>> Block size = 256- 25 =256-224=32 netA: host address range 1 to 30 netB: host address range 33 to 62 netC: host address range 65 to 94 netD: host address range 97 to 126 netE: host address range 129 to 158 Mohannad Al-Hanahnah
  154. 154. In this example, you are given two address / mask combinations, written with theprefix/length notation, which have been assigned to two devices. Your task is todetermine if these devices are on the same subnet or different subnets.??DeviceA: DeviceA and DeviceB have addresses that are part of the same subnet. Mohannad Al-Hanahnah
  155. 155. In all of the previous examples of subnetting, notice that the same subnet mask was applied for all the subnets. This means that each subnet has the same number of available host addresses. You can need this in some cases, but, in most cases, having the same subnet mask for all subnets ends up wasting address space.Subnet is divided into smaller subnets. – Subnet with one mask (/27). – Then further subnet one of the unused /27 subnets into multiple /30 subnets Mohannad Al-Hanahnah
  156. 156. Given the Class C network of, subnet the network in order to create the network in Figure with the host requirements shown.?netA: NetA, NetC, and NetD have a lot of unused host address space. It is possible that this was a deliberate design accounting for future growth, but in many cases this is just wasted address space due to the fact that the same subnet mask is being used for all the subnets. Mohannad Al-Hanahnah
  157. 157. Solution using VLSM::netA: must support 14 hostsnetB: must support 28 hostsnetC: must support 2 hostsnetD: must support 7 hostsnetE: must support 28 hostDetermine what mask allows the required numberof hosts.netA: requires a /28netB: requires a /27netC: requires a /30netD: requires a /28netE: requires a /27 Mohannad Al-Hanahnah
  158. 158. Question: What subnet and broadcast address is the IP address /18a member of?Answer: The interesting octet is the third octet instead of the fourth octet.Block size=256 – 192 = 64.0, 64, 128. The subnet is The broadcast must be 128.0 is the next subnet.Question: A router receives a packet on an interface with a destination address of172.16.46.191/26. What will the router do with this packet? Answer: is a mask, which gives us a block size of 64. Our subnets are then 0, 64, 128, 192. 191 is the broadcast address of the 128 subnet, so a router, by default, will discard any broadcast packets. Mohannad Al-Hanahnah
  159. 159. introduced to improve both address space utilization and routing scalability in theInternet. It was needed because of the rapid growth of the Internet and growth ofthe IP routing tables held in the Internet routers.CIDR moves way from the traditional IP classes (Class A, Class B, Class C, and soon). In CIDR , an IP network is represented by a prefix, which is an IP address andsome indication of the length of the mask.This allows for the summarization of the domains to be done at the higher level. Forexample, if an ISP owns network, then the ISP can offer172.16.1.0/24,, and so on to customers. Yet, when advertising toother providers, the ISP only needs to advertise Mohannad Al-Hanahnah
  160. 160. Summarizing Addresses in a VLSM-Designed Network Mohannad Al-Hanahnah
  161. 161. Classful Routing Overview – Classful routing protocols do not include the subnet mask with the network in the routing advertisement. – Within the same network, consistency of the subnet masks is assumed, one subnet mask for the entire network. – Summary routes are exchanged between foreign networks. – Examples of classful routing protocols include: • RIPv1 • IGRP• Note: Classful routing protocols are legacy routing protocols typically used to address compatibility issues. Mohannad Al-Hanahnah
  162. 162. Classless Routing Overview– Classless routing protocols include the subnet mask with the network in the advertisement.– Classless routing protocols support VLSM; one network can have multiple masks.– Summary routes must be manually controlled within the network.– Examples of classless routing protocols include: • RIPv2 • EIGRP • OSPF Mohannad Al-Hanahnah
  163. 163. Mohannad Al-Hanahnah
  164. 164. Introduction to RoutersA router is a special type of computer. It has the same basic components as astandard desktop PC. However, routers are designed to perform some very specificfunctions. Just as computers need operating systems to run software applications,routers need the Internetwork Operating System software (IOS) to run configurationfiles. These configuration files contain the instructions and parameters that control theflow of traffic in and out of the routers. The many parts of a router are shown below: Mohannad Al-Hanahnah
  165. 165. RAMRandom Access Memory, also called dynamic RAM (DRAM)RAM has the following characteristics and functions:• Stores routing tables• Holds ARP cache• Performs packet buffering (shared RAM)• Provides temporary memory for the configuration file of the router while the router is powered on• Loses content when router is powered down or restarted Mohannad Al-Hanahnah
  166. 166. NVRAMNon-Volatile RAMNVRAM has the following characteristics and functions:• Provides storage for the startup configuration file• Retains content when router is powered down or restarted Mohannad Al-Hanahnah
  167. 167. FlashFlash memory has the following characteristics andfunctions:• Holds the operating system image (IOS)• Allows software to be updated without removing and replacing chips on the processor• Retains content when router is powered down or restarted• Can store multiple versions of IOS software Mohannad Al-Hanahnah
  168. 168. ROMRead-Only MemoryROM has the following characteristics and functions:• Maintains instructions for power-on self test (POST) diagnostics• Stores bootstrap program and basic operating system software Mohannad Al-Hanahnah
  169. 169. Mohannad Al-Hanahnah
  170. 170. InterfacesInterfaces have the following characteristics and functions:• Connect router to network for frame entry and exit• Can be on the motherboard or on a separate moduleTypes of interfaces:• Ethernet• Fast Ethernet• Serial• Token ring• ISDN BRI• Console• Aux Mohannad Al-Hanahnah
  171. 171. Internal Components of a 2600 Router Mohannad Al-Hanahnah
  172. 172. External Components of a 2600 Router Mohannad Al-Hanahnah
  173. 173. External Connections Mohannad Al-Hanahnah
  174. 174. Fixed InterfacesWhen cabling routers for serial connectivity, the routers will either havefixed or modular ports. The type of port being used will affect the syntaxused later to configure each interface. Mohannad Al-Hanahnah
  175. 175. Computer/Terminal Console Connection Mohannad Al-Hanahnah
  176. 176. Router Power-On/Bootup Sequence1. Perform power-on self test (POST).2. Load and run bootstrap code.3. Find the Cisco IOS software.4. Load the Cisco IOS software.5. Find the configuration.6. Load the configuration.7. Run the configured Cisco IOS software. Mohannad Al-Hanahnah
  177. 177. Step in Router Initialization Mohannad Al-Hanahnah
  178. 178. show version CommandRouter#show versionCisco Internetwork Operating System SoftwareIOS (tm) C2600 Software (C2600-JS-M), Version 12.0(7a), RELEASE SOFTWARE (fc1)Copyright (c) 1986-2002 by cisco Systems, Inc.Compiled Tue 05-Feb-02 01:48 by pwadeImage text-base: 0x80008088, data-base: 0x80B0404CROM: System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1)Router uptime is 1 minuteSystem restarted by reloadSystem image file is "flash:c2600-js-mz.120-7a.bin"cisco 2610 (MPC860) processor (revision 0x300) with 53248K/12288K bytes of memory.Processor board ID JAD06090BMD (2719249260)M860 processor: part number 0, mask 49Bridging software.X.25 software, Version 3.0.0.SuperLAT software (copyright 1990 by Meridian Technology Corp).TN3270 Emulation software.Basic Rate ISDN software, Version 1.1.1 Ethernet/IEEE 802.3 interface(s)2 Serial(sync/async) network interface(s)1 ISDN Basic Rate interface(s)32K bytes of non-volatile configuration memory.16384K bytes of processor board System flash (Read/Write)Configuration register is 0x2102 Mohannad Al-Hanahnah
  179. 179. Mohannad Al-Hanahnah
  180. 180. Overview of Router Modes Mohannad Al-Hanahnah
  181. 181. Router Modes Mohannad Al-Hanahnah
  182. 182. User Mode Commands Mohannad Al-Hanahnah
  183. 183. Privileged Mode Commands NOTE: There are many more commands available in privileged mode. Mohannad Al-Hanahnah
  184. 184. Specific Configuration Modes Mohannad Al-Hanahnah
  185. 185. Saving Configurations wg_ro_c# wg_ro_c#copy running-config startup-config Destination filename [startup-config]? Building configuration… wg_ro_c#• Copies the current configuration to NVRAM Mohannad Al-Hanahnah
  186. 186. The copy run tftp Command Mohannad Al-Hanahnah
  187. 187. The copy tftp run Command Mohannad Al-Hanahnah
  188. 188. Configuring Router Identification– Sets the local identity or message for the accessed router or interface Mohannad Al-Hanahnah
  189. 189. Configuring a Router Password Mohannad Al-Hanahnah
  190. 190. Configuring an InterfaceRouter(config)#interface type numberRouter(config-if)#• type includes serial, ethernet, token ring, fddi, hssi, loopback, dialer, null, async, atm, bri, tunnel, and so on• number is used to identify individual interfacesRouter(config)#interface type slot/portRouter(config-if)#• For modular routers, selects an interfaceRouter(config-if)#exit • Quits from current interface configuration mode Mohannad Al-Hanahnah
  191. 191. Configuring an Interface DescriptionRouterX(config-if)# description string string is a comment or a description to help you remember what is attached to this interface. The maximum number of characters for the string argument is 238. Mohannad Al-Hanahnah
  192. 192. Disabling or Enabling an InterfaceRouterX#configure terminalRouterX(config)#interface serial 0RouterX(config-if)#shutdown%LINK-5-CHANGED: Interface Serial0, changed state to administratively down%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to down  Administratively turns off an interfaceRouterX#configure terminalRouterX(config)#interface serial 0RouterX(config-if)#no shutdown%LINK-3-UPDOWN: Interface Serial0, changed state to up%LINEPROTO-5-UPDOWN: Line Protocol on Interface Serial0, changed state to up  Enables an interface that is administratively shut down Mohannad Al-Hanahnah
  193. 193. Serial Interface show controller CommandRouter#show controller serial 0HD unit 0, idb = 0x121C04, driver structure at 0x127078buffer size 1524 HD unit 0, V.35 DTE Cable cable . . . • Shows the cable type of serial cables Mohannad Al-Hanahnah
  194. 194. Setting the Clock with HelpMohannad Al-Hanahnah
  195. 195. Configuring InterfacesAn interface needs an IP Address and a Subnet Mask to be configured.All interfaces are “shutdown” by default.The DCE end of a serial interface needs a clock rate.Router#config tRouter(config)#interface serial 0/1Router(config-if)#ip address rate 56000 (required for serial DCE only)Router(config-if)#no shutdownRouter(config-if)#exitRouter(config)#int f0/0Router(config-if)#ip address shutdownRouter(config-if)#exitRouter(config)#exitRouter# Mohannad Al-Hanahnah
  196. 196. show and debug Commands Mohannad Al-Hanahnah
  197. 197. Examining the show CommandsThere are many show commands that can be used to examine the contents of filesin the router and for troubleshooting. In both privileged EXEC and user EXECmodes, the command show ? provides a list of available show commands. The listis considerably longer in privileged EXEC mode than it is in user EXEC interfaces – Displays all the statistics for all the interfaces on the int s0/1 – Displays statistics for interface Serial 0/1show controllers serial – Displays information-specific to the interface hardwareshow clock – Shows the time set in the routershow hosts – Displays a cached list of host names and addressesshow users – Displays all users who are connected to the routershow history – Displays a history of commands that have been enteredshow flash – Displays info about flash memory and what IOS files are stored thereshow version – Displays info about the router and the IOS that is running in RAMshow ARP – Displays the ARP table of the routershow start – Displays the saved configuration located in NVRAMshow run – Displays the configuration currently running in RAMshow protocol – Displays the global and interface specific status of any configured Layer 3 protocols Mohannad Al-Hanahnah
  198. 198. Cisco Discovery Protocol “CDP”– Cisco Discovery Protocol is a proprietary utility that provides a summary of directly connected switches, routers, and other Cisco devices.– Cisco Discovery Protocol discovers neighboring devices, regardless of which protocol suite they are running. Mohannad Al-Hanahnah
  199. 199. Discovering Neighbors with Cisco Discovery Protocol – Cisco Discovery Protocol runs on Cisco IOS devices. – Summary information includes: – Device identifiers – Address list – Port identifier – Capabilities list – Platform Mohannad Al-Hanahnah
  200. 200. Using Cisco Discovery ProtocolRouterA#show cdp ? entry Information for specific neighbor entry interface CDP interface status and configuration neighbors CDP neighbor entries traffic CDP statistics …RouterA(config)#no cdp run! Disable CDP GloballyRouterA(config)#interface serial0/0/0RouterA(config-if)#no cdp enable! Disable CDP on just this interface Mohannad Al-Hanahnah
  201. 201. Using the show cdp neighbors CommandRouterA#show cdp neighborsCapability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge S - Switch, H - Host, I - IGMP, r - RepeaterDevice ID Local Intrfce Holdtme Capability Platform Port IDSwitchA fa0/0 122 S I WS-C2960 fa0/2RouterB s0/0/0 177 R S I 2811 s0/0/1 Mohannad Al-Hanahnah
  202. 202. Using the show cdp entry CommandDevice ID: RouterBEntry address(es): IP address: Cisco 2811, Capabilities: Router Switch IGMPInterface: Serial0/0/0, Port ID (outgoing port): Serial0/0/1Holdtime : 155 secVersion :Cisco IOS Software, 2800 Software (C2800NM-ADVIPSERVICESK9-M),Version 12.4(12), RELEASE SOFTWARE (fc1)Technical Support: (c) 1986-2006 by Cisco Systems, Inc.Compiled Fri 17-Nov-06 12:02 Mohannad Al-Hanahnah by prod_rel_team
  203. 203. Additional Cisco Discovery Protocol CommandsRouterA#show cdp trafficCDP counters : Total packets output: 8680, Input: 8678 Hdr syntax: 0, Chksum error: 0, Encaps failed: 5 No memory: 0, Invalid packet: 0, Fragmented: 0 CDP version 1 advertisements output: 0, Input: 0 CDP version 2 advertisements output: 8680, Input: 8678RouterA#show cdp interface s0/0/0Serial0/0/0 is up, line protocol is up Encapsulation PPP Sending CDP packets every 60 seconds Holdtime is 180 seconds Mohannad Al-Hanahnah
  204. 204. Mohannad Al-Hanahnah
  205. 205. Anatomy of an IP PacketIP packets consist of the data from upper layers plus an IPheader. The IP header consists of the following: Mohannad Al-Hanahnah
  206. 206. Static vs. Dynamic RoutesRouting is the process that a router uses to forward packets towardthe destination network. A router makes decisions based upon thedestination IP address of a packet. All devices along the way use thedestination IP address to point the packet in the correct direction sothat the packet eventually arrives at its destination. In order to makethe correct decisions, routers must learn the direction to remotenetworks. • Static Route • Dynamic Route –Uses a route that a – Uses a route network routing that a network protocol adjusts administrator automatically for enters into the topology or traffic router manually changes Mohannad Al-Hanahnah
  207. 207. Static Routes• Configure unidirectional static routes to and from a stub network to allow communications to occur. Mohannad Al-Hanahnah
  208. 208. Configuring Static Routes bySpecifying Outgoing Interfaces Mohannad Al-Hanahnah
  209. 209. Configuring Static Routes bySpecifying Next-Hop Addresses Mohannad Al-Hanahnah
  210. 210. Default Routes• This route allows the stub network to reach all known networks beyond router A. Mohannad Al-Hanahnah
  211. 211. Verifying the Static Route Configurationrouter#show ip routeCodes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default U - per-user static routeGateway of last resort is to network is subnetted, 1 subnetsC is directly connected, Serial0S* is directly connected, Serial0 Mohannad Al-Hanahnah
  212. 212. What Is a Dynamic Routing Protocol? Routing protocols are used between routers to determine paths to remote networks and maintain those networks in the routing tables. After the path is determined, a router can route a routed protocol to the learned networks. Mohannad Al-Hanahnah
  213. 213. Autonomous Systems: Interior and Exterior Routing Protocols  An autonomous system is a collection of networks within a common administrative domain.  Interior gateway protocols operate within an autonomous system.  Exterior gateway protocols connect different autonomous systems. Mohannad Al-Hanahnah
  214. 214. Administrative Distance: Ranking Routes Mohannad Al-Hanahnah
  215. 215. Classes of Routing Protocols Mohannad Al-Hanahnah
  216. 216. Classful Routing Protocol– Classful routing protocols do not include the subnet mask with the route advertisement.– Within the same network, consistency of the subnet masks is assumed.– Summary routes are exchanged between foreign networks.– These are examples of classful routing protocols: • RIPv1 • IGRP Mohannad Al-Hanahnah
  217. 217. Classless Routing Protocol– Classless routing protocols include the subnet mask with the route advertisement.– Classless routing protocols support a variable-length subnet mask (VLSM).– Summary routes can be manually controlled within the network.– These are examples of classless routing protocols: • RIPv2 • EIGRP • OSPF • IS-IS Mohannad Al-Hanahnah
  218. 218. Selecting the Best Route Using Metrics Mohannad Al-Hanahnah
  219. 219. Distance Vector Routing Protocols Routers pass periodic copies of their routing table to neighboring routers and accumulate distance vectors. Mohannad Al-Hanahnah
  220. 220. Sources of Information and Discovering RoutesRouters discover the best path to destinations from each neighbor. Mohannad Al-Hanahnah
  221. 221. Maintaining Routing Information Updates proceed step by step from router to router. Mohannad Al-Hanahnah
  222. 222. Inconsistent Routing Entries:Counting to Infinity and Routing Loops Each node maintains the distance from itself to each possible destination network. Mohannad Al-Hanahnah
  223. 223. Counting to InfinitySlow convergence produces inconsistent routing. Mohannad Al-Hanahnah
  224. 224. Counting to Infinity (Cont.) Router C concludes that the best path to network is through router B. Mohannad Al-Hanahnah
  225. 225. Counting to Infinity (Cont.) Router A updates its table to reflect the new but erroneous hop count. Mohannad Al-Hanahnah
  226. 226. Counting to Infinity (Cont.)The hop count for network counts to infinity. Mohannad Al-Hanahnah
  227. 227. Solution to Counting to Infinity: Defining a MaximumA limit is set on the number of hops to prevent infinite loops. Mohannad Al-Hanahnah
  228. 228. Routing LoopsPackets for network bounce(loop) between routers B and C. Mohannad Al-Hanahnah
  229. 229. Solution to Routing Loops: Split Horizon It is never useful to send information about a route back in the direction from which the original information came. Mohannad Al-Hanahnah
  230. 230. Solution to Routing Loops:Route Poisoning and Poison Reverse Routers advertise the distance of routes that have gone down to infinity. Mohannad Al-Hanahnah
  231. 231. Solution to Routing Loops:Route Poisoning and Poison Reverse (Cont.) Poison reverse overrides split horizon. Mohannad Al-Hanahnah
  232. 232. Solution to Routing Loops: Hold-Down TimersThe router keeps an entry for the “possibly down” state in the network,allowing time for other routers to recompute for this topology change. Mohannad Al-Hanahnah
  233. 233. Triggered UpdatesThe router sends updates when a change in its routing table occurs. Mohannad Al-Hanahnah
  234. 234. Link-State Routing ProtocolsAfter an initial flood of LSAs, link-state routers pass small,event-triggered link-state updates to all other routers. Mohannad Al-Hanahnah
  235. 235. OSPF Hierarchical Routing  Consists of areas and autonomous systems  Minimizes routing update traffic Mohannad Al-Hanahnah
  236. 236. Link-State Routing Protocol Algorithms
  237. 237. Benefits and Drawbacks of Link-State Routing– Benefits of link-state routing: • Fast convergence: – Changes are reported immediately by the affected source • Robustness against routing loops: – Routers know the topology – Link-state packets are sequenced and acknowledged • Hierarchical network design enables optimization of resources.– Drawbacks of link-state routing: • Significant demands for resources: – Memory (three tables: adjacency, topology, forwarding) – CPU • Requires very strict network design • Configuration can be complex when tuning various parameters and when design is complex Mohannad Al-Hanahnah
  238. 238. RIP Overview– Hop-count metric selects the path– Routes update every 30 seconds– Administrative distance 120
  239. 239. RIPv1 and RIPv2 Comparison RIPv1 RIPv2Routing protocol Classful ClasslessSupports variable-length subnet mask? No YesSends the subnet mask along with the routing No Yesupdate?Addressing type Broadcast Multicast RFCs 1721, 1722,Defined in … RFC 1058 and 2453Supports manual route summarization? No YesAuthentication support? No Yes
  240. 240. RIP ConfigurationRouterX(config)# router rip–Starts the RIP routing processRouterX(config-router)# version 2 Enables RIP version 2RouterX(config-router)# network network-number Selects participating attached networks Requires a major classful network number Mohannad Al-Hanahnah
  241. 241. RIP Configuration Example Mohannad Al-Hanahnah
  242. 242. Verifying the RIP ConfigurationA#show ip protocolRouting Protocol is "rip" Sending updates every 30 seconds, next due in 6 seconds Invalid after 180 seconds, hold down 180, flushed after 240 Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Redistributing: rip Default version control: send version 2, receive version 2 Interface Send Recv Triggered RIP Key-chain FastEthernet0/0 2 2 Serial0/0/2 2 2 Automatic network summarization is in effect Maximum path: 4 Routing for Networks: Routing Information Sources: Gateway Distance Last Update 120 00:00:25 Distance: (default is 120)Mohannad Al-Hanahnah
  243. 243. Displaying the IP Routing TableRouterA# show ip routeCodes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default U - per-user static route, o - ODR T - traffic engineered routeGateway of last resort is not set is subnetted, 1 subnetsC is directly connected, fastethernet0/0 is subnetted, 2 subnetsR [120/1] via, 00:00:07, Serial0/0/2C is directly connected, Serial0/0/2R [120/2] via, 00:00:07, Serial0/0/2 Mohannad Al-Hanahnah
  244. 244. debug ip rip CommandRouterA# debug ip ripRIP protocol debugging is onRouterA#00:06:24: RIP: received v1 update from on Serial0/0/200:06:24: in 1 hops00:06:24: in 2 hops00:06:33: RIP: sending v1 update to via FastEthernet0/0 ( network, metric 100:06:34: network, metric 300:06:34: RIP: sending v1 update to via Serial0/0/2 ( network, metric 1 Mohannad Al-Hanahnah
  245. 245. EIGRP Features Advanced distance vector  Flexible network design Rapid convergence  Multicast and unicast instead of broadcast Easy configuration address Incremental updates  Support for VLSM and discontiguous subnets  Support for multiple network layer protocols Mohannad Al-Hanahnah
  246. 246. EIGRP Tables Mohannad Al-Hanahnah
  247. 247. EIGRP Path Calculation (Router C) Mohannad Al-Hanahnah
  248. 248. EIGRP ConfigurationRouterX(config)# router eigrp autonomous-systemRouterX(config-router)# network network-number Mohannad Al-Hanahnah
  249. 249. EIGRP and Discontiguous Networks with no auto-summary Mohannad Al-Hanahnah
  250. 250. Verifying the EIGRP ConfigurationRouterX# show ip route eigrp Displays the current EIGRP entries in the routing tableRouterX# show ip protocols Displays the parameters and current state of the active processRouterX# show ip eigrp interfaces Displays information about interfaces configured for EIGRP Mohannad Al-Hanahnah
  251. 251. Verifying the EIGRP Configuration (Cont.)RouterX# show ip eigrp neighbors Displays the neighbors discovered by IP EIGRP Mohannad Al-Hanahnah
  252. 252. Verifying the EIGRP Configuration (Cont.)RouterX# show ip eigrp topology Displays the IP EIGRP topology table Mohannad Al-Hanahnah
  253. 253. Verifying the EIGRP Configuration (Cont.)RouterX# show ip eigrp traffic Displays the number of IP EIGRP packets sent and received Mohannad Al-Hanahnah
  254. 254. debug ip eigrp CommandRouterX# debug ip eigrpIP-EIGRP: Processing incoming UPDATE packetIP-EIGRP: Ext M 386560 - 256000 130560 SM 360960 –256000 104960IP-EIGRP: Ext M 386560 - 256000 130560 SM 360960 –256000 104960IP-EIGRP: Ext M 386560 - 256000 130560 SM 360960 –256000 104960IP-EIGRP:, - do advertise out Ethernet0/1IP-EIGRP: Ext metric 371200 - 256000 115200IP-EIGRP:, - do advertise out Ethernet0/1IP-EIGRP: Ext metric 46310656 - 45714176 596480IP-EIGRP:, - do advertise out Ethernet0/1IP-EIGRP: Ext metric 2272256 - 1657856 614400IP-EIGRP:, - do advertise out Ethernet0/1IP-EIGRP: Ext metric 40622080 - 40000000 622080IP-EIGRP:, - do advertise out Ethernet0/1 Note: EIGRP routes are exchanged only when a change in topology occurs. Mohannad Al-Hanahnah
  255. 255. EIGRP Metric• The criteria that EIGRP uses by default to calculate its metric: – Bandwidth – Delay• The optional criteria that EIGRP can be configured to use when calculating its metric: – Reliability – Load• Note: Although MTU is exchanged in EIGRP packets between neighbor routers, MTU is not factored into the EIGRP metric calculation. Mohannad Al-Hanahnah
  256. 256. EIGRP Load Balancing– By default, EIGRP does equal-metric load balancing: • By default, up to four routes with a metric equal to the minimum metric are installed in the routing table.– There can be up to 16 entries in the routing table for the same destination: • The number of entries is configurable with the maximum-paths command. Mohannad Al-Hanahnah
  257. 257. OSPF Overview– (OSPF) is an open standard routing protocol– Creates a neighbor relationship by exchanging hello packets– Floods LSAs to all OSPF routers in the area, not just directly connected routers– Pieces together all the LSAs generated by the OSPF routers to create the OSPF link-state database– Uses the SPF algorithm to calculate the shortest path to each destination and places it in the routing table Mohannad Al-Hanahnah
  258. 258. OSPF Hierarchy Example Minimizes routing table entries Localizes the impact of a topology change within an area Mohannad Al-Hanahnah
  259. 259. Neighbor Adjacencies: The Hello Packet Mohannad Al-Hanahnah
  260. 260. SPF Algorithm 10 10 1 1 1 Places each router at the root of a tree and calculates the shortest path to each destination based on the cumulative cost Cost = Reference Bandwidth / Interface Bandwidth (b/s) Mohannad Al-Hanahnah
  261. 261. Configuring WildcardsIf you want to advertise a partial octet (subnet), you need to use wildcards. – means all octets match exactly – means that the first three match exactly, but the last octet can be any valueAfter that, you must remember your block sizes…. Mohannad Al-Hanahnah
  262. 262. WildcardThe wildcard address is always one less than the block size…. – = – = – = – = Mohannad Al-Hanahnah
  263. 263. Configuring Single-Area OSPFRouterX(config)#router ospf process-id Defines OSPF as the IP routing protocolRouterX(config-router)#network address wildcard-mask area area-id Assigns networks to a specific OSPF area Mohannad Al-Hanahnah
  264. 264. Verifying the OSPF ConfigurationRouter#show ip protocols• Verifies that OSPF is configuredRouter#show ip route• Displays all the routes learned by the routerRouter#show ip ospf interface• Displays area-ID and adjacency informationRouter#show ip ospf neighbor• Displays OSPF-neighbor information on a per-interface basis Mohannad Al-Hanahnah
  265. 265. Administrative Distances Mohannad Al-Hanahnah
  266. 266. Classful and Classless Routing Protocols Mohannad Al-Hanahnah
  267. 267. Routing ProtocolComparison Chart Mohannad Al-Hanahnah
  268. 268. Mohannad Al-Hanahnah
  269. 269. Ethernet Switches and Bridges – Address learning – Forward/filter decision – Loop avoidance Mohannad Al-Hanahnah
  270. 270. Transmitting FramesCut-Through Store and Forward • Switch checks destination address Complete frame is received and and immediately begins checked before forwarding. forwarding frame.Fragment-Free • Switch checks the first 64 bytes, then immediately begins forwarding frame. Mohannad Al-Hanahnah
  271. 271. Layer 2 Addressing– MAC address– Assigned to end devices Mohannad Al-Hanahnah
  272. 272. MAC Address Table• Initial MAC address table is empty. Mohannad Al-Hanahnah
  273. 273. Learning Addresses• Station A sends a frame to station C.• Switch caches the MAC address of station A to port E0 by learning the source address of data frames.• The frame from station A to station C is flooded out to all ports except port E0 (unknown unicasts are flooded). Mohannad Al-Hanahnah
  274. 274. Learning Addresses (Cont.)• Station D sends a frame to station C.• Switch caches the MAC address of station D to port E3 by learning the source address of data frames.• The frame from station D to station C is flooded out to all ports except port E3 (unknown unicasts are flooded). Mohannad Al-Hanahnah
  275. 275. Filtering Frames• Station A sends a frame to station C.• Destination is known; frame is not flooded. Mohannad Al-Hanahnah
  276. 276. Filtering Frames (Cont.)• Station A sends a frame to station B.• The switch has the address for station B in the MAC address table. Mohannad Al-Hanahnah
  277. 277. ARPMohannad Al-Hanahnah
  278. 278. ARP Table Mohannad Al-Hanahnah
  279. 279. Host-to-Host Packet Delivery (1 of 22) Mohannad Al-Hanahnah
  280. 280. Host-to-Host Packet Delivery (2 of 22) Mohannad Al-Hanahnah
  281. 281. Host-to-Host Packet Delivery (3 of 22) Mohannad Al-Hanahnah
  282. 282. Host-to-Host Packet Delivery (4 of 22) Mohannad Al-Hanahnah
  283. 283. Host-to-Host Packet Delivery (5 of 22) Mohannad Al-Hanahnah
  284. 284. Host-to-Host Packet Delivery (6 of 22) Mohannad Al-Hanahnah
  285. 285. Host-to-Host Packet Delivery (7 of 22) Mohannad Al-Hanahnah
  286. 286. Host-to-Host Packet Delivery (8 of 22) Mohannad Al-Hanahnah
  287. 287. Host-to-Host Packet Delivery (9 of 22) Mohannad Al-Hanahnah
  288. 288. Host-to-Host Packet Delivery (10 of 22) Mohannad Al-Hanahnah
  289. 289. Host-to-Host Packet Delivery (11 of 22) Mohannad Al-Hanahnah
  290. 290. Host-to-Host Packet Delivery (12 of 22) Mohannad Al-Hanahnah
  291. 291. Host-to-Host Packet Delivery (13 of 22) Mohannad Al-Hanahnah
  292. 292. Host-to-Host Packet Delivery (14 of 22) Mohannad Al-Hanahnah
  293. 293. Host-to-Host Packet Delivery (15 of 22) Mohannad Al-Hanahnah
  294. 294. Host-to-Host Packet Delivery (16 of 22) Mohannad Al-Hanahnah
  295. 295. Host-to-Host Packet Delivery (17 of 22) Mohannad Al-Hanahnah
  296. 296. Host-to-Host Packet Delivery (18 of 22) Mohannad Al-Hanahnah
  297. 297. Host-to-Host Packet Delivery (19 of 22) Mohannad Al-Hanahnah
  298. 298. Host-to-Host Packet Delivery (20 of 22) Mohannad Al-Hanahnah
  299. 299. Host-to-Host Packet Delivery (21 of 22) Mohannad Al-Hanahnah
  300. 300. Host-to-Host Packet Delivery (22 of 22) Mohannad Al-Hanahnah
  301. 301. Default Gateway Mohannad Al-Hanahnah
  302. 302. Host-Based Tools: ping Mohannad Al-Hanahnah
  303. 303. Host-Based Tools: Table Mohannad Al-Hanahnah
  304. 304. Host-Based Tools: tracert Mohannad Al-Hanahnah
  305. 305. Mohannad Al-Hanahnah
  306. 306. Redundant Topology Redundant topology eliminates single points of failure. Redundant topology causes broadcast storms, multiple frame copies, and MAC address table instability problems. Mohannad Al-Hanahnah
  307. 307. Broadcast Frames Station D sends a broadcast frame. Broadcast frames are flooded to all ports except the originating port. Mohannad Al-Hanahnah
  308. 308. Broadcast Storms Host X sends a broadcast. Switches continue to propagate broadcast traffic over and over. Mohannad Al-Hanahnah
  309. 309. Multiple Frame Copies Host X sends a unicast frame to router Y. The MAC address of router Y has not been learned by either switch. Router Y will receive two copies of the same frame. Mohannad Al-Hanahnah
  310. 310. MAC Database Instability Host X sends a unicast frame to router Y. The MAC address of router Y has not been learned by either switch. Switches A and B learn the MAC address of host X on port 1. The frame to router Y is flooded. Switches A and B incorrectly learn the MAC address of host X on port 2. Mohannad Al-Hanahnah
  311. 311. Loop Resolution with STP Provides a loop-free redundant network topology by placing certain ports in the blocking state Published in the IEEE 802.1D specification Enhanced with the Cisco PVST+ implementation Mohannad Al-Hanahnah
  312. 312. Spanning-Tree Operation One root bridge per broadcast domain. One root port per nonroot bridge. One designated port per segment. Nondesignated ports are unused. Mohannad Al-Hanahnah
  313. 313. STP Root Bridge Selection BPDU (default = sent every 2 seconds) Root bridge = bridge with the lowest bridge ID Bridge ID = Bridge MAC Priority Address Mohannad Al-Hanahnah
  314. 314. Spanning-Tree Port StatesSpanning tree transits each port through several different states: Mohannad Al-Hanahnah
  315. 315. • Describe the role of STP port states and BPDU timers in the operation of STP Mohannad Al-Hanahnah
  316. 316. Describing PortFastPortFast is configured on access ports, not trunk ports. Mohannad Al-Hanahnah
  317. 317. Configuring and Verifying PortFastSwitchX(config-if)#spanning-tree portfast Configures PortFast on an interface ORSwitchX(config)#spanning-tree portfast default Enables PortFast on all non-trunking interfacesSwitchX#show running-config interface interface Verifies that PortFast has been configured on an interface Mohannad Al-Hanahnah
  318. 318. Spanning-Tree Operation Example Mohannad Al-Hanahnah
  319. 319. Spanning-Tree Path Cost Cost (New IEEE Cost (Old IEEE Link Speed Specification) Specification)10 Gb/s 2 11 Gb/s 4 1100 Mb/s 19 1010 Mb/s 100 100 Mohannad Al-Hanahnah
  320. 320. Spanning-Tree Recalculation Mohannad Al-Hanahnah
  321. 321. Per VLAN Spanning Tree Plus Mohannad Al-Hanahnah
  322. 322. PVST+ Extended Bridge IDBridge ID without theextended system IDExtended bridge IDwith system IDSystem ID = VLAN Mohannad Al-Hanahnah
  323. 323. Rapid Spanning Tree Protocol Mohannad Al-Hanahnah
  324. 324. Default Spanning-Tree Configuration– Cisco Catalyst switches support three types of STPs: • PVST+ • PVRST+ • MSTP– The default STP for Cisco Catalyst switches is PVST+ : • A separate STP instance for each VLAN • One root bridge for all VLANs • No load sharing Mohannad Al-Hanahnah
  325. 325. PVRST+ Configuration Guidelines1. Enable PVRST+.2. Designate and configure a switch to be the root bridge.3. Designate and configure a switch to be the secondary root bridge.4. Verify the configuration. Mohannad Al-Hanahnah
  326. 326. PVRST+ Implementation CommandsSwitchX(config)#spanning-tree mode rapid-pvst Configures PVRST+SwitchX#show spanning-tree vlan vlan# [detail] Verifies the spanning-tree configurationSwitchX#debug spanning-tree pvst+ Displays PVST+ event debug messages Mohannad Al-Hanahnah
  327. 327. Verifying PVRST+SwitchX# show spanning-tree vlan 30VLAN0030Spanning tree enabled protocol rstpRoot ID Priority 24606Address 00d0.047b.2800This bridge is the rootHello Time 2 sec Max Age 20 sec Forward Delay 15 secBridge ID Priority 24606 (priority 24576 sys-id-ext 30)Address 00d0.047b.2800Hello Time 2 sec Max Age 20 sec Forward Delay 15 secAging Time 300Interface Role Sts Cost Prio.Nbr Type-------- ----- --- --- -------- ----Gi1/1 Desg FWD 4 128.1 P2pGi1/2 Desg FWD 4 128.2 P2pGi5/1 Desg FWD 4 128.257 P2pThe spanning-tree mode is set to PVRST. Mohannad Al-Hanahnah
  328. 328. Configuring the Root and Secondary Bridges Mohannad Al-Hanahnah