Chapter 8 Interconnecting Networks with TCPIP 2000 Cisco

Chapter 8 Interconnecting Networks with TCP/IP © 2000, Cisco Systems, Inc. 8 -1

Objectives Upon completion of this chapter you will be able to perform the following tasks: • Identify the IP protocol stack, its protocol layer functions, and commonly used IP protocols • Identify IP address classes, IP addresses, IP subnet masks, IP network numbers, subnet numbers, and possible host numbers. • Configure IP addresses and subnet masks on a router interface and optionally configure a host table. • Interconnect the VLANs with a layer three device such as a router on a stick. © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -3

Introduction to TCP/IP Host Internet TCP/IP Early protocol suite Universal © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -4

TCP/IP Protocol Stack 7 Application 6 Presentation 5 Session 4 Transport 3 Network Internet 2 Data Link 1 Physical 5 Application 4 3 2 1 © 2000, Cisco Systems, Inc. Physical www. cisco. com ICND v 1. 0 a— 8 -5

Application Layer Overview Application Transport Internet Data Link Physical © 2000, Cisco Systems, Inc. File Transfer - TFTP * - NFS E-Mail - SMTP Remote Login - Telnet * - rlogin * Network Management - SNMP * Name Management - DNS* *Used by the router www. cisco. com ICND v 1. 0 a— 8 -6

Transport Layer Overview Application Transport Internet Transmission Control Protocol (TCP) Connection. Oriented User Datagram Protocol (UDP) Connectionless Data Link Physical © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -7

TCP Segment Format Bit 0 Bit 15 Bit 16 Bit 31 Destination port (16) Source port (16) Sequence number (32) Acknowledgement number (32) Header length (4) Reserved (6) Code bits (6) Checksum (16) 20 Bytes Window (16) Urgent (16) Options (0 or 32 if any) Data (varies) © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -8

Port Numbers Application Layer Transport Layer © 2000, Cisco Systems, Inc. F T P T E L N E T S M T P D N S T F T P S N M P R I P 21 23 25 53 69 161 520 Port Numbers UDP TCP www. cisco. com ICND v 1. 0 a— 8 -9

TCP Port Numbers Source Port Dest. Port … Telnet Z Host A © 2000, Cisco Systems, Inc. SP DP 1028 23 … www. cisco. com Dest. port = 23. Send packet to my Telnet application. ICND v 1. 0 a— 8 -10

UDP Segment Format Bit 1 0 Bit 15 Bit 16 Bit 31 Destination port (16) Source port (16) Length (16) 8 Bytes Checksum (16) Data (if any) No sequence or acknowledgment fields © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -11

Internet Layer Overview Internet Protocol (IP) Application Transport Internet Data Link Physical Internet Control Message Protocol (ICMP) Address Resolution Protocol (ARP) Reverse Address Resolution Protocol (RARP) OSI network layer corresponds to the TCP/IP internet layer © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -12

IP Datagram Bit 1 0 Version (4) Bit 15 Bit 16 Header Length (4) Priority & Type of Service (8) Total Length (16) Flags (3) Identification (16) Time to live (8) Bit 31 Protocol (8) Fragment offset (13) Header checksum (16) 20 Bytes Source IP Address (32) Destination IP Address (32) Options (0 or 32 if any) Data (varies if any) © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -13

Protocol Field Transport Layer UDP TCP 6 Internet Layer 17 Protocol Numbers IP Determines destination upper-layer protocol © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -14

Internet Control Message Protocol Application Destination Unreachable Transport 1 ICMP Echo (Ping) Internet Other Data Link Physical © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -15

Address Resolution Protocol I need the Ethernet address of 176. 16. 3. 2. 172. 16. 3. 1 172. 16. 3. 2 IP: 172. 16. 3. 2 = ? ? ? © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -16

Address Resolution Protocol I need the Ethernet address of 176. 16. 3. 2. I heard that broadcast. The message is for me. Here is my Ethernet address. 172. 16. 3. 1 172. 16. 3. 2 IP: 172. 16. 3. 2 = ? ? ? © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -17

Address Resolution Protocol I need the Ethernet address of 176. 16. 3. 2. I heard that broadcast. The message is for me. Here is my Ethernet address. 172. 16. 3. 1 172. 16. 3. 2 IP: 172. 16. 3. 2 = ? ? ? IP: 172. 16. 3. 2 Ethernet: 0800. 0020. 1111 © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -18

Address Resolution Protocol I need the Ethernet address of 176. 16. 3. 2. I heard that broadcast. The message is for me. Here is my Ethernet address. 172. 16. 3. 1 172. 16. 3. 2 IP: 172. 16. 3. 2 = ? ? ? IP: 172. 16. 3. 2 Ethernet: 0800. 0020. 1111 Map IP MAC Local ARP © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -19

Reverse ARP What is my IP address? Ethernet: 0800. 0020. 1111 IP = ? ? ? © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -20

Reverse ARP I heard that broadcast. Your IP address is 172. 16. 3. 25. What is my IP address? Ethernet: 0800. 0020. 1111 IP = ? ? ? © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -21

Reverse ARP I heard that broadcast. Your IP address is 172. 16. 3. 25. What is my IP address? Ethernet: 0800. 0020. 1111 IP = ? ? ? Ethernet: 0800. 0020. 1111 IP: 172. 16. 3. 25 © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -22

Reverse ARP I heard that broadcast. Your IP address is 172. 16. 3. 25. What is my IP address? Ethernet: 0800. 0020. 1111 IP = ? ? ? Ethernet: 0800. 0020. 1111 IP: 172. 16. 3. 25 Map MAC © 2000, Cisco Systems, Inc. www. cisco. com IP ICND v 1. 0 a— 8 -23

Introduction to TCP/IP Addresses 172. 18. 0. 1 172. 18. 0. 2 10. 13. 0. 0 10. 13. 0. 1 172. 16. 0. 1 HDR SADA DATA 172. 17. 0. 1 172. 16. 0. 2 172. 17. 0. 2 192. 168. 1. 0 192. 168. 1. 1 • Unique addressing allows communication between end stations • Path choice is based on destination address Location is represented by an address © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -24

IP Addressing 32 bits Dotted Decimal Maximum © 2000, Cisco Systems, Inc. Network 255 www. cisco. com Host 255 ICND v 1. 0 a— 8 -25

IP Addressing 32 bits Dotted Decimal Network 255 Maximum 1 Host 255 8 9 255 16 17 255 24 25 32 128 64 32 16 8 4 2 1 © 2000, Cisco Systems, Inc. www. cisco. com 128 64 32 16 8 4 2 1 11111111 Binary ICND v 1. 0 a— 8 -26

IP Addressing 32 bits Dotted Decimal Network 255 Maximum 1 255 8 9 255 16 17 255 24 25 32 128 64 32 16 8 4 2 1 11111111 128 64 32 16 8 4 2 1 Binary Host Example 172 16 122 204 Decimal Example 10101100 00010000 01111010 1100 Binary © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -27

IP Address Classes 8 bits Host Host Class A: Network Class B: Network Class C: Network Class D: Multicast Class E: Research © 2000, Cisco Systems, Inc. www. cisco. com Host ICND v 1. 0 a— 8 -28

IP Address Classes Bits: Class A: Bits: Class B: Bits: Class C: Bits: Class D: © 2000, Cisco Systems, Inc. 1 8 9 0 NNNNNNN 16 17 24 25 Host 32 Host Range (1 -126) 1 8 9 10 NNNNNN 16 17 Network Range (128 -191) 1 8 9 110 NNNNN Host 16 17 Network Range (192 -223) 1 8 9 1110 MMMM 24 25 Host 24 25 Network 16 17 32 32 Host 24 25 32 Multicast Group Range (224 -239) www. cisco. com ICND v 1. 0 a— 8 -29

Host Addresses 172. 16. 2. 2 172. 16. 3. 10 10. 1. 1. 1 10. 6. 24. 2 E 1 E 0 172. 16. 2. 1 10. 250. 8. 11 172. 16. 12 172. 16 Network © 2000, Cisco Systems, Inc. . 12. 12 Host 10. 180. 30. 118 Routing Table Network Interface 172. 16. 0. 0 E 0 10. 0 E 1 www. cisco. com ICND v 1. 0 a— 8 -30

Determining Available Host Addresses 16 0 0 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 172 Host . . . 10101100 0001000000000001 00000011 N 1 2 3 . . . Network 11111101 65534 11111110 65535 11111111 65536 2 2 N-2 = 216 -2 = 65534 © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -31

IP Address Classes Exercise Address Class Network Host 10. 2. 1. 1 128. 63. 2. 100 201. 222. 5. 64 192. 6. 141. 2 130. 113. 64. 16 256. 241. 201. 10 © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -32

IP Address Classes Exercise Answers Address Class 10. 2. 1. 1 A 10. 0 0. 2. 1. 1 128. 63. 2. 100 B 128. 63. 0. 0. 2. 100 201. 222. 5. 64 C 201. 222. 5. 0 0. 0. 0. 64 192. 6. 141. 2 C 192. 6. 141. 0 0. 0. 0. 2 130. 113. 64. 16 B 130. 113. 0. 0. 64. 16 256. 241. 201. 10 Nonexistent © 2000, Cisco Systems, Inc. Network www. cisco. com Host ICND v 1. 0 a— 8 -33

Addressing without Subnets 172. 16. 0. 1 172. 16. 0. 2 172. 16. 0. 3 172. 16. 255. 254 …. . . 172. 16. 0. 0 Network 172. 16. 0. 0 © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -34

Addressing with Subnets 172. 16. 3. 0 172. 16. 4. 0 172. 16. 1. 0 172. 16. 2. 0 Network 172. 16. 0. 0 © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -35

Subnet Addressing 172. 16. 2. 200 172. 16. 2. 2 172. 16. 3. 5 172. 16. 3. 1 E 0 172. 16. 2. 1 172. 16. 3. 100 172. 160 172. 16 Network © 2000, Cisco Systems, Inc. . 172. 16. 3. 150 2. 160 New Routing Table Network Interface Host 172. 16. 0. 0 E 0 172. 16. 0. 0 E 1 www. cisco. com ICND v 1. 0 a— 8 -36

Subnet Addressing 172. 16. 2. 200 172. 16. 3. 5 172. 16. 3. 1 E 0 172. 16. 2. 1 172. 16. 2. 2 172. 16. 3. 100 172. 160 172. 16 Network © 2000, Cisco Systems, Inc. . 2 Subnet 172. 16. 3. 150 . 160 Host New Routing Table Network Interface 172. 16. 2. 0 E 0 172. 16. 3. 0 E 1 www. cisco. com ICND v 1. 0 a— 8 -37

Subnet Mask Network IP ress 172 Host 16 0 Network fault bnet Mask 8 -bit bnet Mask © 2000, Cisco Systems, Inc. 0 Host 255 0 0 255 255 0 11111111 00000000 Also written as “/16” where 16 represents the number of 1 s in the mask. Network Subnet Host Also written as “/24” where 24 represents the number of 1 s in the mask. www. cisco. com ICND v 1. 0 a— 8 -38

Decimal Equivalents of Bit Patterns 128 64 32 16 8 4 2 1 0 0 0 0 = 0 1 0 0 0 0 = 128 1 1 0 0 0 = 192 1 1 1 0 0 0 = 224 1 1 0 0 = 240 1 1 1 0 0 0 = 248 1 1 1 0 0 = 252 1 1 1 1 0 = 254 1 1 1 1 = 255 © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -39

Subnet Mask without Subnets Network Host 172. 160 10101100 000100000010 10100000 255. 0. 0 11111111 00000000 10101100 000100000000 172 16 0 0 Network Number Subnets not in use—the default © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -40

Subnet Mask with Subnets Network 172. 160 Host 10101100 000100000010 10100000 11111111 0000 10101100 000100000010 0000 172 16 128 192 224 240 248 252 254 255. 0 Subnet Network Number 2 0 Network number extended by eight bits © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -41

Subnet Mask with Subnets (cont. ) 255. 192 Network Number Host 10101100 000100000010 10100000 11111111 11000000 10101100 000100000010 10000000 128 192 224 240 248 252 254 255 172. 160 Subnet 128 192 224 240 248 252 254 255 Network 172 16 2 128 Network number extended by ten bits © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -42

Subnet Mask Exercise Address Subnet Mask 172. 16. 2. 10 255. 0 10. 6. 24. 20 255. 240. 0 10. 36. 12 255. 0 © 2000, Cisco Systems, Inc. www. cisco. com Class Subnet ICND v 1. 0 a— 8 -43

Subnet Mask Exercise Answers Address Subnet Mask Class Subnet 172. 16. 2. 10 255. 0 B 172. 16. 2. 0 10. 6. 24. 20 255. 240. 0 A 10. 6. 16. 0 10. 36. 12 255. 0 A 10. 36. 0 © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -44

Broadcast Addresses 172. 16. 3. 0 172. 16. 4. 0 172. 16. 1. 0 172. 16. 2. 0 172. 16. 3. 255 (Directed broadcast) 255 (Local network broadcast) X 172. 16. 255 (All subnets broadcast) © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -45

Addressing Summary Example 172. 160 172 16 10101100 00010000 2 160 00000010 10100000 Host 1 Mask 255. 192 Subnet 4 Broadcast First Last © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -46

Addressing Summary Example 172 16 172. 160 10101100 000100000010 10100000 Host 255. 192 11111111 11000000 Mask 2 2 160 1 Subnet Broadcast First Last © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -47

Addressing Summary Example 172 160 3 172. 160 10101100 000100000010 10100000 Host 255. 192 11111111 11000000 Mask 2 1 Subnet Broadcast First Last © 2000, Cisco Systems, Inc. www. cisco. com 7 ICND v 1. 0 a— 8 -48

Addressing Summary Example 172 160 3 172. 160 10101100 000100000010 10100000 Host 255. 192 11111111 11000000 Mask 2 1 10000000 Subnet 4 Broadcast First Last © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -49

Addressing Summary Example 172 160 3 172. 160 10101100 000100000010 10100000 Host 255. 192 11111111 11000000 Mask 2 1 10000000 Subnet 4 10111111 Broadcast 5 First 6 Last © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -50

Addressing Summary Example 172 160 3 172. 160 10101100 000100000010 10100000 Host 255. 192 11111111 11000000 Mask 2 1 10000000 Subnet 4 10111111 Broadcast 5 10000001 First 6 Last © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -51

Addressing Summary Example 172 160 3 172. 160 10101100 000100000010 10100000 Host 255. 192 11111111 11000000 Mask 2 1 10000000 Subnet 4 10111111 Broadcast © 2000, Cisco Systems, Inc. www. cisco. com 5 10000001 First 6 10111110 Last 7 ICND v 1. 0 a— 8 -52

Addressing Summary Example 172 160 3 10101100 000100000010 10100000 Host 255. 192 1111 8 11111111 11000000 Mask 2 10101100 000100000010 10000000 Subnet 4 10101100 000100000010 10111111 Broadcast 10101100 00010000 5 00000010 10000001 First 6 10101100 000100000010 10111110 Last 7 172. 160 © 2000, Cisco Systems, Inc. www. cisco. com 1 ICND v 1. 0 a— 8 -53

Addressing Summary Example 172 160 3 10101100 000100000010 10100000 Host 255. 192 1111 8 9 172. 16. 2. 128 10101100 11111111 11000000 Mask 2 000100000010 10000000 Subnet 4 10101100 000100000010 10111111 Broadcast 6 7 172. 160 172. 16. 2. 191 172. 16. 2. 129 10101100 00010000 5 00000010 10000001 First 172. 16. 2. 190 10101100 000100000010 10111110 Last © 2000, Cisco Systems, Inc. www. cisco. com 1 ICND v 1. 0 a— 8 -54

Class B Subnet Example IP Host Address: 172. 16. 2. 121 Subnet Mask: 255. 0 Network Subnet Host 172. 16. 2. 121: 10101100 000100000010 01111001 255. 0: 11111111 0000 Subnet: 10101100 000100000010 0000 Broadcast: 10101100 000100000010 1111 Subnet Address = 172. 16. 2. 0 Host Addresses = 172. 16. 2. 1– 172. 16. 2. 254 Broadcast Address = 172. 16. 2. 255 Eight bits of subnetting © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -55

Subnet Planning 20 subnets 5 hosts per subnet Class C address: 192. 168. 5. 0 192. 168. 5. 16 Other subnets 192. 168. 5. 32 © 2000, Cisco Systems, Inc. 192. 168. 5. 48 www. cisco. com ICND v 1. 0 a— 8 -56

Class C Subnet Planning Example IP Host Address: 192. 168. 5. 121 Subnet Mask: 255. 248 Network Subnet Host 192. 168. 5. 121: 11000000 10101000 00000101 01111001 255. 248: 11111111 11111000 Subnet: 11000000 Broadcast: 11000000 10101000 00000101 01111111 Subnet Address = 192. 168. 5. 120 Host Addresses = 192. 168. 5. 121– 192. 168. 5. 126 Broadcast Address = 192. 168. 5. 127 Five Bits of Subnetting © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -57

Broadcast Addresses Exercise Address Subnet Mask 201. 222. 10. 60 255. 248 15. 16. 193. 6 255. 248. 0 128. 16. 32. 13 255. 252 153. 50. 6. 27 255. 128 © 2000, Cisco Systems, Inc. Class www. cisco. com Subnet Broadcast ICND v 1. 0 a— 8 -58

Broadcast Addresses Exercise Answers Address Subnet Mask Class Subnet Broadcast 201. 222. 10. 60 255. 248 C 201. 222. 10. 56 201. 222. 10. 63 15. 16. 193. 6 255. 248. 0 A 15. 16. 192. 0 15. 16. 199. 255 128. 16. 32. 13 255. 252 B 128. 16. 32. 12 128. 16. 32. 15 153. 50. 6. 27 255. 128 B 153. 50. 6. 0 153. 50. 6. 127 © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -59

Switch IP Address Configuration Switch(config)#ip address ip-address subnet-mask • Assigns an address and subnet mask • Starts IP processing on a switch Switch(config)#ip default-gateway ip-address • Specifies a default gateway © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -60

Router IP Address Configuration Router(config-if)#ip address ip-address subnet-mask • Assigns an address and subnet mask • Starts IP processing on a router interface © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -61

Router IP Address Configuration Router#term ip netmask-format {bitcount| decimal | hexadecimal} • Sets display format of network mask for current session Router(config-line)#ip netmask-format {bitcount | decimal | hexadecimal} • Sets format of network mask for a specific line © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -62

Router IP Host Names Router(config)#ip host name [tcp-port-number] address [address] • Defines static host name to IP address mapping ip host Norine 172. 16. 3. 1 192. 168. 3. 1 ip host Roger 172. 16. 4. 3 • Hosts/interfaces selectable by name or IP address © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -63

Router Name Server Configuration DNS Server Router(config)#ip name-server-address 1 [[server-address 2]. . . [server-address 6]] • Specifies one or more hosts that supply host name to logical address resolution © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -64

Router Name System Router(config)#ip domain-lookup Router(config)#end Router#pat Translating ”pat". . . domain server (255. 255) % Unknown command or computer name, or unable to find computer address Router#config t Router(config)#no ip domain-lookup Router(config)#end Router#pat Translating ”pat" % Unknown command or computer name, or unable to find computer address Router# • DNS enabled by default © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -65

Router Display Host Names Router#show hosts Default domain is not set Name/address lookup uses domain service Name servers are 255 Host Norine Roger Frank Bob Flags (perm, OK) OK) Age Type 0 IP Address(es) 172. 16. 100. 101 172. 16. 200. 201 • Shows the host table © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -66

VLAN to VLAN Overview Fa 0/0 ISL VLAN 1 Router on a stick VLAN 2 Application 10. 1. 1. 2 10. 2. 2. 2 TCP IP ISL Ethernet Network layer devices combine multiple broadcast domains © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -67

Dividing a Physical Interface into Subinterfaces Fast. Ethernet 0/0. 1 Fast. Ethernet 0/0. 2 Fast. Ethernet 0/0. 3 Physical interfaces can be divided into multiple subinterfaces © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -68

ISL Encapsulation Router(config-subif)#encapsulation isl vlan identifier • Enables ISL on a subinterface © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -69

Routing Between VLANs Fast E 0/0 ISL VLAN 1 10. 1. 1. 2 © 2000, Cisco Systems, Inc. VLAN 2 10. 2. 2. 2 interface fastethernet 0/0 no ip address ! interface fastethernet 0/0. 1 ip address 10. 1. 1. 1 255. 0 encapsulation isl 1 interface fastethernet 0/0. 2 ip address 10. 2. 2. 1 255. 0 encapsulation isl 2 www. cisco. com ICND v 1. 0 a— 8 -70

Routing Between WANs S 0 ISL 172. 16. 1. 1 VLAN 1 10. 1. 1. 2 VLAN 2 Application 10. 2. 2. 2 interface Serial 0 ip address 172. 16. 1. 1 255. 0 © 2000, Cisco Systems, Inc. 172. 16. 1. 2 www. cisco. com TCP IP HDLC Serial ICND v 1. 0 a— 8 -71

Visual Objective SUBNET 10. 1. 1. 0 10. 2. 2. 0 10. 3. 3. 0 10. 4. 4. 0 10. 5. 5. 0 10. 6. 6. 0 10. 7. 7. 0 10. 8. 8. 0 10. 9. 9. 0 10. 10. 0 10. 11. 0 10. 12. 0 10. 13. 0 VLAN 1 2 3 4 5 6 7 8 9 10 11 12 13 POD wg_ro_x, wg_sw_x, core_sw_a, core_sw_b wg_pc_a, core_server, core_ro wg_pc_b, core_server, core_ro wg_pc_c, core_server, core_ro wg_pc_d, core_server, core_ro wg_pc_e, core_server, core_ro wg_pc_f, core_server, core_ro wg_pc_g, core_server, core_ro wg_pc_h, core_server, core_ro wg_pc_i, core_server, core_ro wg_pc_j, core_server, core_ro wg_pc_k, core_server, core_ro wg_pc_l, core_server, core_ro VLAN 2 fa 0/26 e 0/1 (port A) VLAN 13 fa 0/0 fa 0/23 . . . fa 0/1 fa 0/24 core_ server © 2000, Cisco Systems, Inc. wg_pc_l 10. 13. 12 fa 0/27 (port B) wg_sw_l 10. 1. 1. 120 fa 0/12 fa 0/13 core_sw_a fa 0/14 10. 1. 1. 2 www. cisco. com fa 0/27 (port B) wg_sw_a 10. 1. 1. 10 fa 0/26 e 0/1 (port A) Core_ro wg_pc_a 10. 2. 2. 12 fa 0/13 fa 0/14 core_sw_b 10. 1. 1. 4 ICND v 1. 0 a— 8 -72

Summary After completing this chapter, you should be able to perform the following tasks: • Identify the TCP/IP protocol stack and the functions of each layer • Separate an IP address into its subcomponents: the network, subnet, and host portions • Configure IP addresses on Cisco router and switch interfaces • Interconnect VLANs using a layer three device such as a “router on a stick” © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -73

Review Questions 1. What is the difference between the TCP and UDP transport layer protocols? 2. Given a host with IP address, 192. 168. 20. 1 255. 240, how many other hosts can you have in that network? 3. What is required to interconnect separate VLANs? © 2000, Cisco Systems, Inc. www. cisco. com ICND v 1. 0 a— 8 -74