Ch.3 – Configuring a Router

1. Ch.3 – Configuring a Router CCNA 1 version 3.0 Rick Graziani Cabrillo College

2. Note to instructors • If you have downloaded this presentation from the Cisco Networking Academy Community FTP Center, this may not be my latest version of this PowerPoint. • For the latest PowerPoints for all my CCNA, CCNP, and Wireless classes, please go to my web site: http://www.cabrillo.cc.ca.us/~rgraziani/ • The username is cisco and the password is perlman for all of my materials. • If you have any questions on any of my materials or the curriculum, please feel free to email me at graziani@cabrillo.edu (I really don’t mind helping.) Also, if you run across any typos or errors in my presentations, please let me know. • I will add “(Updated – date)” next to each presentation on my web site that has been updated since these have been uploaded to the FTP center. Thanks! Rick Rick Graziani graziani@cabrillo.edu

3. Overview Students completing this module should be able to: • Name a router • Set passwords • Examine show commands • Configure a serial interface • Configure an Ethernet interface • Execute changes to a router • Save changes to a router • Configure an interface description • Configure a message-of-the-day banner • Configure host tables • Understand the importance of backups and documentation Rick Graziani graziani@cabrillo.edu

4. CLI command modes Router#configure terminal Router(config)# Rick Graziani graziani@cabrillo.edu

5. Configuring a router name Router#config t Router(config)#hostname Tokyo Tokyo(config)# Mistake… Should be… Rick Graziani graziani@cabrillo.edu

6. Configuring router passwords Not recommended, clear text Encrypts the passwords above, but… Use this command instead, password is encryped Router(config)#enable secret <password> Rick Graziani graziani@cabrillo.edu

7. service password-encryption command WARNING • service password-encryption uses a Cisco Level 7 encryption which is very easy to decrypt. • For the GetPass! software www.boson.com • However, the enable secret <password> uses a stronger encryption method and cannot be easily hacked. Rick Graziani graziani@cabrillo.edu

8. enable secret <password> command • More later! Doesn’t work for enable secret! Rick Graziani graziani@cabrillo.edu

9. Using exit, end and Control-Z end exit Rick Graziani graziani@cabrillo.edu

10. Using exit, end and Control-Z Router>ena Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#? Configure commands: aaa Authentication, Authorization and Acc.. access-list Add an access list entry alias Create command alias appletalk Appletalk global configuration commands arap Appletalk Remote Access Protocol arp Set a static ARP entry <text omitted> Router(config)#exit 00:03:20: %SYS-5-CONFIG_I: Configured from console by con Router# Router(config)#interface interface Router(config-if)#exit Router(config)#router routing-protocol Router(config-router)#exit Router(config)#exit Router# Must be in privileged mode Message each time you exit “global configuration mode” Rick Graziani graziani@cabrillo.edu

11. Using exit, end and Control-Z Router# conf t (abbreviated) Router(config)# router protocol Router(config-router)# (commands) Router(config-router)# exit Router(config)# exit Router# Router(config)# interface type port Router(config-if)# (commands) Router(config-if)# end (or Control-Z) Router# Rick Graziani graziani@cabrillo.edu

12. Examining the show commands • show interfaces – Displays all the statistics for all the interfaces on the router. To view the statistics for a specific interface, enter the show interfaces command followed by the specific interface and port number. • show controllers serial – Displays information-specific to the interface hardware • show clock – Shows the time set in the router • show hosts – Displays a cached list of host names and addresses • show users – Displays all users who are connected to the router • show history – Displays a history of commands that have been entered • show flash – Displays information about flash memory and what IOS files are stored there • show version – Displays information about the router and the IOS that is running in RAM • show ARP – Displays the ARP table of the router • show protocol – Displays the global and interface specific status of any configured Layer 3 protocols • show startup-configuration – Displays the saved configuration located in NVRAM • show running-configuration – Displays the configuration currently running in RAM Rick Graziani graziani@cabrillo.edu

13. show interfaces <interface> command Router>show interface ethernet 0 Ethernet0 is administratively down, line protocol is down , using hub 0 Hardware is Lance, address is 0010.7b3a.cf84 (bia 0010.7b3a.cf84) MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, rely 255/255, load 1/255 Encapsulation ARPA, loopback not set, keepalive set (10 sec) ARP type: ARPA, ARP Timeout 04:00:00 Last input never, output 01:05:35, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 0 input packets with dribble condition detected 63 packets output, 11676 bytes, 0 underruns 0 output errors, 0 collisions, 1 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out Router> MAC Address Status Routing metric information (later) Data link encapsulation (Ethernet-II) ARP cache entries timer Rick Graziani graziani@cabrillo.edu

14. Where is the MAC Address? Router>show interface serial 0 Serial0 is administratively down, line protocol is down Hardware is HD64570 MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation HDLC, loopback not set, keepalive set (10 sec) Last input never, output never, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 28 packets output, 9576 bytes, 0 underruns 0 output errors, 0 collisions, 17 interface resets 0 output buffer failures, 0 output buffers swapped out 0 carrier transitions DCD=down DSR=down DTR=down RTS=down CTS=down Router> Rick Graziani graziani@cabrillo.edu

15. Examining the show commands • We will log into a router a examine some of the show commands. Rick Graziani graziani@cabrillo.edu

16. Configuring a serial interface Router(config)#interface serial 0/0 Router(config-if)#ip address <ip address> <netmask> Configuring an IP Address on an interface… Rick Graziani graziani@cabrillo.edu

17. show ip interface command • A serial interface will not show “up” and “up” unless both ends are properly configured (mostly) and a the no shutdown command is used. • If one router’s configuration looks okay, check the other router’s configuration. Router# show ip interface brief Interface IP-Address OK? Method Status Protocol Ethernet0 131.108.1.11 YES manual up up Serial0 198.135.2.49 YES manual administratively down down What is wrong here? The administrator has either done a “shutdown” on the interface or has forgotten to do a “no shutdown”. Rick Graziani graziani@cabrillo.edu

18. Configuring a serial interface Lab • On serial links that are directly interconnected, as in a lab environment, one side must be considered a DCE and provide a clocking signal. • The clock is enabled and speed is specified with the clock rate command. Router(config)#interface serial 0/0 Router(config-if)#clock rate 56000 Router(config-if)#no shutdown Real world Rick Graziani graziani@cabrillo.edu

19. Configuring a serial interface RouterB(config)#inter serial 1 RouterB(config-if)#clock rate ? Speed (bits per second) 1200 2400 4800 9600 19200 38400 56000 64000 <text omitted> 2000000 4000000 <300-4000000> Choose clockrate from list above RouterB(config-if)#clock rate 64000 RouterB(config-if)# RouterA DTE cable RouterB DCE cable Rick Graziani graziani@cabrillo.edu

20. Configuring a serial interface DTE Cable DCE Cable How can you tell which end is the DTE and which end is the DCE? • Look at the label on the cable. • Look at the connecter between the two cables - The DTE cable will always be male and the DCE cable will always be female. Rick Graziani graziani@cabrillo.edu

21. Configuring a serial interface RouterA#show controllers serial 0 HD unit 0, idb = 0xECA4C, driver structure at 0xF1EC8 buffer size 1524 HD unit 0, V.35 DTE cable cpb = 0x62, eda = 0x403C, cda = 0x4050 RX ring with 16 entries at 0x624000 00 bd_ptr=0x4000 pak=0x0F5704 ds=0x62FFB8 status=80 pak_size=22 RouterB#show controllers serial 0 buffer size 1524 HD unit 0, V.35 DCE cable, clockrate 64000 cpb = 0x62, eda = 0x408C, cda = 0x40A0 RX ring with 16 entries at 0x624000 00 bd_ptr=0x4000 pak=0x0F2F04 ds=0x627908 status=80 pak_size=22 RouterA DTE cable RouterB DCE cable This is one of few commands where there must be a space between the interface type and the port. How can you tell which end is the DTE and which end is the DCE? • Use the show controllers command! • It will also tell you the type of cable, in our labs we will be using a V.35 cable. Rick Graziani graziani@cabrillo.edu

22. Configuring a serial interface • Please be very careful when connecting the male and female V.35 cables together AND when connecting the serial cable to the router! • They only connect ONE WAY! • Be sure the two ends match! • Don’t force it! This end up! (The wider end is up.) Rick Graziani graziani@cabrillo.edu

23. Executing adds, moves, and changes running-config startup-config IOS Bootup program IOS (running) ios (partial) Rick Graziani graziani@cabrillo.edu

24. Executing adds, moves, and changes Router#show startup-config %% Non-volatile configuration memory is not present Router#show running-config Building configuration... Current configuration: ! version 12.0 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname Router ! ip subnet-zero ! ! interface Ethernet0 no ip address no ip directed-broadcast shutdown ! interface Serial0 no ip address no ip directed-broadcast shutdown No startup-config file in NVRAM Default running-config file, created in RAM Rick Graziani graziani@cabrillo.edu

25. The running-config Executing adds, moves, and changes • The configuration file contains global, process, and interface information that directly affects the operation of the router and its interface ports. • All changes to the router are made to the running-config file and take affect immediately on the router (with just a couple of exceptions). • IP address • Routing Protocols • Router’s Name • etc. Router#show running-config Building configuration... Current configuration: ! version 12.0 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname Router ! ip subnet-zero ! interface Ethernet0 no ip address no ip directed-broadcast shutdown Rick Graziani graziani@cabrillo.edu

26. copy running-config startup-config • Changes to the router are automatically put in the running-config file. • If the router loses power or reboots, everything in RAM is lost including the running-config file. • To make sure the changes to the router’s configuration remain saved, you must copy the running-config from RAM into the startup-config into NVRAM: Router# copy running-config startup-config During bootup running-config RAM startup-config Router# copy running-config startup-config Rick Graziani graziani@cabrillo.edu

27. copy running-config startup-config Router#copy running-config startup-config Destination filename [startup-config]? Building configuration... Router#show startup-config ! version 12.0 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname Router ! ! ip subnet-zero ! interface Ethernet0 no ip address no ip directed-broadcast shutdown ! The startup-config file now identical to running-config and the router will also have these changes if the router reboots. Rick Graziani graziani@cabrillo.edu

28. copy running-config startup-config Router# copy running-config startup-config Or Router# copy running startup OR Router# copy run start OR Any usage of the command or parameters, so that they are still uniquely recognizable. WARNING • Using an incorrect configuration file name could overwrite the router’s IOS in flash, as the router believes you are trying to copy a blank file into flash. Router#copy running-config start-up **** NOTICE **** Flash load helper v1.0 This process will accept the copy options and then terminate the current system image to use the ROM based image for the copy. Routing functionality will not be available during that time. If you are logged in via telnet, this connection will terminate. Users with console access can see the results of the copy operation. ---- ******** ---- Proceed? [confirm]^C %Copy cancelled by user request. Router# Incorrect file name! Press <control> C Rick Graziani graziani@cabrillo.edu

29. copy running-config startup-config Router# copy running-config startup-config Or Router# copy running startup OR Router# copy run start OR Any usage of the command or parameters, so that they are still uniquely recognizable. WARNING • This is also incorrect, and will overwrite the startup-config with a blank file. Router#copy runningconfig startup-config Destination filename [startup-config]? ?Bad filename Router# Incorrect file name! Press <control> C Rick Graziani graziani@cabrillo.edu

30. Displaying the config files show running-config show startup-config 1 These commands can only be done in privilege mode because they display password information. Rick Graziani graziani@cabrillo.edu

31. Executing adds, moves, and changes Rick Graziani graziani@cabrillo.edu

32. Configuring Interfaces Router(config-if)#exit Router(config)#interface serial 0 Router(config-if)#ip add 172.16.10.1 255.255.255.0 Router(config-if)#clock rate 64000 (only if DCE) Router(config-if)#no shutdown Rick Graziani graziani@cabrillo.edu

33. Finishing the Configuration Rick Graziani graziani@cabrillo.edu

34. Importance of configuration standards • In order to manage a network, there must be a centralized support standard. • Configuration, security, performance, and other issues must be adequately addressed for the network to function smoothly. • Creating standards for network consistency helps reduce network complexity, the amount of unplanned downtime, and exposure to events that may have an impact on network performance. Rick Graziani graziani@cabrillo.edu

35. Interface descriptions RouterB#show inter e 0 Serial0 is up, line protocol is up Hardware is HD64570 Description: Engineering LAN, Bldg. 18 Internet address is 10.1.1.1/24 Rick Graziani graziani@cabrillo.edu

36. Interface descriptions Gateway(config)#inter e 0 Gateway(config-if)#description LAN interface for Marketing Gateway(config-if)#end Gateway# Gateway#show run Building configuration... <text omitted> ! interface Ethernet0 description LAN interface for Marketing no ip address no ip directed-broadcast shutdown <text omitted> Gateway#show interface ethernet 0 Ethernet0 is administratively down, line protocol is down Hardware is Lance, address is 0000.0c34.9ebb (bia 0000.0c34.9ebb) Description: LAN interface for Marketing MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, rely 252/255, load 1/255 Encapsulation ARPA, loopback not set, keepalive set (10 sec) ARP type: ARPA, ARP Timeout 04:00:00 <text omitted> Gateway#copy run start Destination filename [startup-config]? Building configuration... Gateway# Don’t forget this or next time router reboots these changes will be lost! Rick Graziani graziani@cabrillo.edu

37. Configuring interface description Rick Graziani graziani@cabrillo.edu

38. Login banners and Configuring message-of-the-day (MOTD) Wording is not the same, but you get the idea. Rick Graziani graziani@cabrillo.edu

39. Login banners and Configuring message-of-the-day (MOTD) Router(config)#hostname Gateway Gateway(config)# Gateway(config)#banner motd # Enter TEXT message. End with the character '#'. Warning! Stay away! # Gateway(config)#end Gateway#exit Press RETURN to get started. Warning! Stay away! User Access Verification Password: Gateway#show run Building configuration... <text omitted> ! hostname Gateway ! <text omitted> ! banner motd ^C Warning! Stay away! ^C Prompt changes MOTD (Message Of The Day) Delimiter always shows as “^C” Rick Graziani graziani@cabrillo.edu

40. Host name resolution Router# ping 172.16.32.1 Router# ping Auckland Router# telnet 192.168.53.1 Router# telnet Beirut Router# traceroute 192.168.89.1 Router# traceroute Capetown • The Cisco IOS software maintains a cache of host name-to-address mappings for use by EXEC commands. • This cache speeds up the process of converting names to addresses. • Host names, unlike DNS names, are significant only on the router on which they are configured. (DNS is also an option – later) Rick Graziani graziani@cabrillo.edu

41. Host name resolution • This does not make the router a DNS (Domain Name Server). • This command does not turn your router into a DNS server. • This command does not effect packets entering your router to be routed. • This only affects the IOS commands entered at the router prompt. • Multiple ip addresses can be entered in case one interface is down. • It is usually a good idea to use the same list of names on all your router configs. Configuring Multiple IP Addresses Router(config)# ip host SantaCruz 172.16.32.1 192.168.53.1 Rick Graziani graziani@cabrillo.edu

42. Configuring host tables Rick Graziani graziani@cabrillo.edu

43. If you are not using the services of a DNS server, it is best to disable this process. • DNS (Domain Name Service) is enabled by default with a server address of 255.255.255.255, which is a local broadcast. • If enabled, with no DNS server on the network, may cause a slight, but irritable delay when making typing mistakes. Router(config)# ip domain-lookup Router#wreh Translating "wreh"...domain server (255.255.255.255) (Takes a few seconds) Translating "wreh"...domain server (255.255.255.255) (Takes a few seconds) Router(config)# no ip domain-lookup Router#wreh Translating "wreh" % Unknown command or computer name, or unable to find computer address Rick Graziani graziani@cabrillo.edu

44. Configuration backup and documentation • Configuration files should be stored as backup files in the event of a problem. • Configuration files can be stored on a network server, on a TFTP server, or on a disk stored in a safe place. Rick Graziani graziani@cabrillo.edu

45. Copying, editing, and pasting configurations • A TFTP server will allow image and configuration uploads and downloads over the network. • The TFTP server can be another router, or it can be a host system. Rick Graziani graziani@cabrillo.edu

46. Copying, editing, and pasting configurations • The TFTP host can be any system that has TFTP software loaded and operating and able to receive files from the TCP/IP network. Rick Graziani graziani@cabrillo.edu

47. Copying, editing, and pasting configurations startup-config running-config IOS RAM IOS (running) copy flash tftp copy tftp flash copy startup-config tftp copy tftp startup-config copy running-config tftp copy tftp running-config Rick Graziani graziani@cabrillo.edu

48. Copying, editing, and pasting configurations • Troubleshooting: Be sure you can ping the TFTP server. Rick Graziani graziani@cabrillo.edu

49. TFTP Software and Servers • When using Windows, the TFTP server software must be running. • The copy can be performed from the console port or from a telnet session. • The telnet session can be performed on the same computer where the TFTP server is running (or to a different computer). Router# copy flash tftp Rick Graziani graziani@cabrillo.edu

50. TFTP Software and Servers • TFTP software either comes free with the OS (Linux/Unix) or can be downloaded for free. Rick Graziani graziani@cabrillo.edu