1. TCP/IP Address Overview End stations communicate seamlessly with servers or other stations Each node uses a unique 32 bit IP address

2. IP Datagrams Include a unique source IP address and Destination IP address IP addresses identify the source and destination network and host

3. Internetwork Each company listed on the internetwork must be reached before an individual host within that company can be contacted Host populating that network share the same network bits but are identified by a uniqueness of the remaining bits

4. IP Address 32 bits in length Contains two parts –Network number –Host number Binary in nature Expressed in a format that can be read by the human eye

5. IP Address Sections Broken into 4 sections of 8 bits called octets Each octet is converted to decimal format and is separated by dots 255.255.255.255 11111111|11111111|11111111|11111111 172.16.122.204 10101100|00010000|01111010|11001100

6. Octets Minimum octet value is 0 – all zeros Maximum octet value is 255 – all ones

7. Address Allocation Addresses are allocated by a central authority, the American Registry of Internetwork Numbers (ARIN) See www.arin.net for more informationwww.arin.net

8. Early IP Addresses Early IP addresses did not use classes because there weren’t very many networks Now a class system is necessary to increase the number of available IP addresses

9. IP Address Classes 8 Bits Class ANetworkHost Class BNetwork Host Class CNetwork Host Class DMulticast Class EResearch

10. Analysis of Class System Class A networks have only 8 network bits and 24 host field bits Therefore, there are few Class A networks There are more Class B networks and even more yet Class C networks each with fewer hosts Class system allows addresses to be assigned based on the size of the network There are many more small networks than there are large networks

11. Address Classification Bits:1 89 1617 2425 32 Class A:0NNNNNNNHost Range(1–126) Bits:1 89 1617 2425 32 Class B:10NNNNNNNetworkHost Range(128–191) Bits:19 1617 2425 32 Class C110NNNNNNetwork Host Range(192–223)

12. Class Ranges Class AClass BClass C Starts with:010110 Range:1.0.0.0 to 126.0.0.0 128.0.0.0 to 191.255.0.0 192.0.0.0 to 223.255.255.0 Networks:127 (1-126) 127 is reserved 16,3842,097,152 Hosts:16,777,216 – 265,536 – 2256 – 2

13. Class D – Multicast Addresses Bits:1 89 1617 2425 32 Class D:1110MMMMMulticast Grp Range(224–239) Includes the following range of network numbers: 224.0.0.0 to 239.255.255.255

14. Class E – Research Addresses Bits:1 89 1617 2425 32 Class E:11110RRRResearch Grp Range(240–247) Includes the following range of network numbers: 240.0.0.0 to 247.255.255.255

15. Reserved Addresses RFC 1918 defines the following as reserved addresses: 10.0.0.0 through 10.255.255.255 172.16.0.0 through 172.31.255.255 192.168.0.0 through 192.168.255.255

16. Host Addresses 10.250.8.11 Router 10.6.24.2 E1 10.180.30.118 172.16.2.100 E0 172.16.2.1 172.16.12.12 172.16.3.10 10.1.1.1 RoutingTable NetworkInterface 172.16.0.0E0 10.0.0.0E1

17. Host Address Conventions Host address of 0 means this network or wire address, i.e., 172.16.0.0 Router uses network address to identify subnet Routing table contains entries for each network All 1s is a broadcast address. Number of addresses in network is 2 N – 2

18. Default Subnet Masks ClassFormatDefault Subnet Mask Anetwork.node.node.node255.0.0.0 Bnetwork.network.node.node255.255.0.0 Cnetwork.network.network.node255.255.255.0

19. Subnet Example 172.16.3.100 Router 172.16.3.1 E1 172.16.3.150 172.16.2.200 E0 172.16.2.1 172.16.2.160 172.16.2.2 172.16.3.5 RoutingTable NetworkInterface 172.16.2.0E0 172.16.3.0E1

20. Subnet Mask Example network host IP Address1721600 network host Default Mask 255 00 written as:/16 network subnethost Subnet Mask 255 0 written as:/24

21. Subnet Mask Numbering 1 for network bits 1 for subnet bits 0 for host bits

22. Methods of Representation Dotted Decimal – 172.16.0.0 255.255.0.0 Bit Count – 172.16.0.0/16 Hexadecimal – 172.16.0.0xFFFF0000

23. Possible Subnet Mask Values 10000000=128 11000000=192 11100000=224 11110000=240 11111000=248 11111100=252 11111110=254 11111111=255

24. Calculating Network Number – No Subnet Bits /16 network host 172.16.2.16010101100000100000000001010100000 255.255.0.011111111 00000000 101011000001000000000000 Network Number1721600

25. Calculating Subnet Number – 8 Subnet Bits /24 network host 172.16.2.16010101100000100000000001010100000 255.255.0.011111111 00000000 10101100000100000000001000000000 Subnet Number1721620

26. Calculating Subnet Number – 10 Subnet Bits /26 network subnethost 172.16.2.1601010110000010000000000 10100000 255.255.0.011111111 000000 1010110000010000000000 10000000 Subnet Number17216 2128

27. Class B Broadcasts From 172.16.1.12 Local to Subnet 1 – 255.255.255.255 Specific to Subnet 3 – 172.16.3.255 To All Subnets – 172.16.255.255

28. Defining Class B Subnet – /26 172.16.2.160101011000001000000000010 10100000host 255.255.255.19211111111 11111111 11000000mask 172.16.2.128101011000001000000000010 10000000subnet 172.16.2.191101011000001000000000010 10111111broadcast 171.16.2.129101011000001000000000010 10000001first 171.16.2.190101011000001000000000010 10111110last

29. Defining Class B Subnet – /24 172.16.2.12110101100000100000000001010100000host 255.255.255.011111111 00000000mask 172.16.2.010101100000100000000001000000000subnet 172.16.2.25510101100000100000000001011111111broadcast 171.16.2.110101100000100000000001000000001first 171.16.2.25410101100000100000000001011111110last

30. Possible Class B Combinations bitssubnet masksubnetshosts 2255.255.192.0216382 3255.255.224.068190 4255.255.240.0144094 5255.255.248.0302046 6255.255.252.0621022 7255.255.254.0126510 8255.255.255.0254 9255.255.255.128510126 10255.255.255.192102262 11255.255.255.224204630 12255.255.255.240409414 13255.255.255.24881906 14255.255.255.252163822

31. Network Design Class C Network with address 172.16.2.121 Supports at least 20 subnets – 5 bits Each Subnet has at least 5 hosts – 3 bits

32. Class C Network Specifications – /29 network subnethost 192.168.5.12111000000101010000000010101111001host 255.255.255.24811111111 11111000mask 192.168.5.12011000000101010000000010101111000subnet 192.168.5.12711000000101010000000010101111111broadcast 192.168.5.12111000000101010000000010101111001first 192.168.5.12611000000101010000000010101111110last

33. Possible Class C Combinations bitssubnet masksubnetshosts 2255.255.255.192262 3255.255.255.224630 4255.255.255.24014 5255.255.255.248306 6255.255.255.252622

34. Configuring IP Addresses Assign logical network address and default gateway to a switch Assign logical network address to a router interface Specify the subnet mask format Assign host names to IP addresses Define name servers Display a list of host names and addresses

35. Logical Network Address – Switch Use ip address global command to establish a logical network on a series 1900 switch: Switch(confid)#ip address ip-address subnet mask –ip-address is a 32-bit dotted-decimal number –subnet-mask is a 32-bit dotted-decimal number used to identify the network/subnet or host

36. Default Gateway Use the ip default-gateway command to define a default gateway on a switch such as the Catalyst 1900 series Switch(config)#ip default-gateway ip-address

37. Logical Network Address – Router Use the router ip address interface configuration command to establish a logical network address on a router interface Router(config-if)#ip address ip-address subnet-mask

38. Subnet Mask Format show commands display an IP address and subnet mask in dotted decimal, bit count or hexadecimal notation. Subnet masks are displayed in dotted decimal notation by default To specify a format for the current session: Router#term ip netmask-format {bitcount|decimal|hexadecimal} To specify a format for a specific line: Router(config-line)#ip netmask-format {bitcount|decimal|hexadecimal} Although you can display subnet masks in bitcount, decimal, and hexadecimal formats, you can only configure an IP and subnet mask with the dotted decimal format

39. Assigning Host Names Cisco IOS software maintains a table of host names and their corresponding address that is called the host name-to-address mapping Higher-layer protocols such as Telnet might use host names to identify network devices (hosts) Host names and IP addresses can be associated through either static or dynamic means

40. Manual Host Name Examples The following manually assigns a hostname: Router(config-line)#ip host name [tcp-port-number] address [address] Name is the name that describes the host location tcp-port-number is an optional TCP number that identifies the TCP port to use with EXEC connect or Telnet command address is the IP address where the name can be reached. Each device can have up to eight different addresses to identify a host

41. Host Name Examples Example 1 – associates the name Norine with two IP addresses. The router will attempt to connect with 172.16.3.1 first when Telnetting to Norine Router(config-line)#ip host Norine 172.16.3.1 192.168.3.1 Example 2 – associates the name Roger with 172.16.3.1 Router(config-line)#ip host Roger 172.16.3.1

42. Defining Name Servers The ip name-server command defines which hosts can provide name service A maximum of six IP addresses can be specified: Router(config)#ip name-server server address [server address]

43. Domain Lookup Router(config)#ip domain-lookup Router(config)#end Router#pat Translating “pat” … domain server (255.255.255.255) % 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#

44. Displaying Host Names and Addresses Router#show hosts Default domain is not set Name/address lookup uses domain service Name servers are 255.255.255.255 HostFlagsAgeTypeAddress(es) Norine(perm, OK)0IP172.16.100.100 Roger(perm, OK)0IP172.16.100.101 Frank(perm, OK)0IP172.16.200.200 Bob(Perm, OK)0IP172.16.200.201

45. Show Hosts Fields Show hosts Command FieldDescription HostNames of learned hosts FlagsHow host info was learned and status permManually configured in static host table tempAcquired from DNS use OKEntry is current ExEntry has aged out (expired) AgeTime measured in hours since software referred to entry TypeProtocol field Address(es)Logical addresses associated with name of host

46. Inter-VLAN Routing Routers can be used to interconnect networks with IP In a switched VLAN, packets are switched only between ports in the same “broadcast domain” Inter VLAN communication cannot occur without a network layer device (router) Router attached to a core switch is called a “router on a stick”

47. VLAN Routing Using ISL 10.2.2.2 Fast E0/0 ISL Router on a Stick 10.1.1.2 VLAN 2 VlAN 1 Switch

48. VLAN Routing Requirements Router must know how to reach all interconnected VLANs Each end device must be addressed with a network layer address such as an IP address The router already knows about directly connected networks. It must learn routes to networks that are not directly connected There must be a separate physical connection for each VLAN or trunking must be enabled on a single physical connection (Chapter 8)

49. ISL Router Configuration interface fastethernet 0/0 no ip address ! interface fastethernet 0/0.1 ip address 10.1.1.1 255.255.255.0 encapsulation isl 1 interface fastethernet 0/0.2 ip address 10.2.2.2 255.255.255.0 encapsulation isl 2

50. To Configure “Router on a Stick” Enable ISL on the switch port connecting to the router Enable ISL encapsulation on the router’s Fast Ethernet subinterface Assign a network layer address to each subinterface Note: the router must sometimes learn routes either statically or dynamically (Chapter 8)

51. Routing Across a WAN 10.2.2.2 ISL Router 10.1.1.2 VLAN 2 VlAN 1 Switch Router 172.16.1.1 S0 172.16.1.2

52. To Set Up a WAN Connection Encapsulate a dat link searial WAN protocol on the WAN interface Assign a network layer address to each interface or subinterface interface Serial0 ip address 172.16.1.1 255.255.255.0

53. TCP/IP Command Summary CommandDescription ip addressSets a switch or router interface IP host address ip default-gatewayDefines a default gateway at the 1900 switch term ip netmask- format Changes the subnet mask output for a session ip netmask-formatChanges the subnet mask output for a line ip hostAllows static association of a IP host name to an address ip name-serverSets the DNS server no ip domain-lookupPrevents the router from doing IP name lookups encapsulation islDefines ISL encapsulation on an Ethernet interface