1. 1 Data Forwarding Basic Router Configuration

2. Overview In this session, we sill be looking at  Review : router backplane Ethernet, console and serial interfaces  Configuring router interfaces Ethernet and serial interface  Viewing router configurations Using show commands  Testing network connectivity Using ping command RD-CSY1017-07/082

3. 3 Addressing - Review

4. 4 What is Routing? Routing - Selecting the correct path towards destination  Build Routing table for path selection  Two methods Static Dynamic Router 1 2 3 0111 value in arriving packet’s header routing algorithm local forwarding table header valueoutput link 0100 0101 0111 1001 32213221

5. 5 Routers –Interfaces Routers have  LAN interfaces Ethernet interfaces:  Have MAC Addresses  IP addresses  WAN interfaces Serial interfaces Have IP addresses Serial 0 192.168.10.1 255.255.255.252 Ethernet 1172.16.2.1/ 255.255.255.0 MAC: 0abbccddeeff Ethernet 0 172.16.1.1/ 255.255.255.0 MAC: 0cddeeffaabb

6. 6 Review: Cisco Router backplane Identify the different interfaces on router  Interface 1  Interface 2  Interface 3  Interface 4 Serial interface console interface Ethernet interface Interface 1 Interface 2 Interface 3 Interface 4

7. Router Components RAM –  holds packet buffers,  routing table,  running-config is stored in RAM, ROM – starts and maintains the router Flash memory – holds the IOS;  is not erased when the router is reloaded; is an EEPROM [Electrically Erasable Programmable Read-Only Memory] NVRAM – Non-Volatile RAM - holds router configuration; is not erased when router is reloaded

8. Where Is The Configuration? Can also be stored in more permanent places: External hosts, using TFTP (Trivial File Transfer Protocol) In flash memory in the router Copy command is used to move it around copy run start  copy run tftp  copy start tftp  copy tftp start  copy flash start  copy start flash

9. Identify network boundaries 128.143.10.33/24 255.255.255.0 RR Can you identify different networks and network addresses ? Identify network class What is the maximum number of hosts that can be hosts can be connected on each of these networks?

10. 10 Review: Establishing a Hyper-terminal Session All Cisco routers include an EIA/TIA-232 asynchronous serial console port (RJ-45). How do you connect to router to configure? Router configured from PC connected to router console port using a rollover cable Rollover cable has Serial interface adapter on one side and RJ45 adapter on the other PC Serial adapter RJ45 adapter

11. RD-CSY1017-07/08 Routing Types Example: Static Routing

12. 12 Connections to the Router- cables Connections of a Router for Ethernet  2 types of cables can be used: Straight through and Cross- over  Straight through used to connect dissimilar devices Switch-to-Router, Switch-to-PC,  Cross-over used to connect similar devices: Switch-to-Switch, Router to PC (Host) PC-to-PC, Switch-to-Hub, Hub-to-Hub, Router-to-Router Cross-overStraight-thru

13. Logging Into The Router Connect router to console port or telnet to router – router> – router>enable – password – router# – router#? Configuring the router – Terminal (entering the commands directly) – router# configure terminal – router(config)# USER MODE PROMPT PRIVILEDGED MODE PROMPT

14. 14 Configuring router Interfaces  -By default all interfaces are down Ethernet Serial  Interface configured with IP address and subnet mask  No Shutdown command used to enable the interface Ethernet interface

15. New Router Configuration Process Load configuration parameters into RAM Router#configure terminal Personalize router identification Router#(config)hostname RouterA Assign access passwords RouterA#(config)line console 0 RouterA#(config-line)password cisco RouterA#(config-line)login

16. RD-CSY1017-07/0816 To configure an Ethernet interface  -Enter interface configuration mode (config)  -Enter IP address and subnet mask  -Enter no shutdown command  Example: -R2(config)#interface fastethernet 0/0 -R2(config-if)#ip address 172.16.1.1 255.255.255.0 -R2(config-if)#no shutdown Configuring Interfaces –Ethernet Interface

17. 17 Configuring Interfaces – Serial Interface Configuring a Serial interface  -Enter interface configuration mode  -Enter in the ip address and subnet mask  -Enter in the no shutdown command Example:  -R1(config)#interface serial 0/0  -R1(config-if)#ip address 172.16.2.1 255.255.255.0  -R1(config-if)#no shutdown

18. 18 Configuring serial links in a lab environment  Serial Interfaces require a clock signal to control the timing of the communications  One end of serial interface is DCE end and other end is DTE end  configure timing on the DCE end of serial interface.  R1# show interface serial 0/0 If it is DCE interface then configure clock rate -R1(config)#interface serial 0/0 -R1(config-if)#clock rate 64000 Serial Interface – setting clock rate

19. 19 Verify configuration Use show commands  -Show interfaces fastEthernet 0/0  -Show ip interface brief  -Show running-config

20. RD-CSY1017-07/0820 Testing the network connectivity To check the connectivity  Run ‘ping’ command Between Host 1 and Host 3 Host 1 and router Host 2 and router Host 3 and router

21. 21 Review: Default Gateway When a LAN is connected to a Router, Default Gateway is the address of router interface connected to that LAN. The IP address and subnet mask is on the same network as the hosts on that network Router LAN Router Default Gateway

22. Global Configuration Static route creation:  IP route n.n.n.n = network block m.m.m.m = network mask denoting block size g.g.g.g = next hop gateway destination packets are sent to

23. 23 Static Routes

24. The NO Command Used to reverse or disable commands e.g ip domain-lookup no ip domain-lookup router ospf 1 no router ospf 1 ip address 1.1.1.1 255.255.255.0 no ip address

25. Looking At The Configuration Use “show running-configuration” to see the current configuration Use “show startup-configuration” to see the configuration in NVRAM, that will be loaded the next time the router is rebooted or reloaded

26. Getting Online Help IOS has a built-in help facility; use “?” to get a list of possible configuration statements “?” after the prompt lists all possible commands:  router#? “ ?” lists all possible subcommands, e.g.:  router#show ?  router#show ip ?

27. Getting Online Help This also works in configuration mode:  router(config)#ip a?  accounting-list accounting-threshold accounting-transits address-pool alias as-path  router(config)#int e0/0  router(config-if)#ip a?  access-group accounting address

28. Getting Lazy Help TAB character will complete a partial word  hostel-rtr(config)#int  hostel-rtr(config)#interface et  hostel-rtr(config)#interface ethernet 0  hostel-rtr(config-if)#ip add  hostel-rtr(config-if)#ip address... n.n.n.n m.m.m.m Not really necessary; partial commands can be used:  router#conf t  router(config)#int e0/0  router(config-if)#ip addr n.n.n.n

29. Deleting Your Router’s Configuration To delete your router’s configuration  Router#erase startup-config  Router#reload  Router will startup again, but in setup mode, since startup-config file does not exists

30. How many Static Routes? 30

31. Conclusion Today we learnt to Configure router interfaces  Ethernet and Serial  Set clock rate on serial interface  Set up and tested the testbed network Design IP addressing Configure ethernet interfaces Verified configurations used ping to test network RD-CSY1017-07/0831