Ch 3 Configuring a Router CCNA 1 version

Ch. 3 – Configuring a Router CCNA 1 version 3. 0 Rick Graziani Cabrillo College

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 Power. Point. • For the latest Power. Points 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 Graziani graziani@cabrillo. edu 2

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 3

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

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

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 6

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

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

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

Using exit, end and Control-Z Router>ena Must be in privileged mode 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 Router(config-if)#exit Router(config)#router routing-protocol Router(config-router)#exit Router(config)#exit Router# Rick Graziani graziani@cabrillo. edu Message each time you exit “global configuration mode” 10

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 11

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 12

show interfaces <interface> command MAC Address Router>show interface ethernet 0 Status Ethernet 0 is administratively down, line protocol is down , using hub 0 Hardware is Lance, address is 0010. 7 b 3 a. cf 84 (bia 0010. 7 b 3 a. cf 84) MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, rely 255/255, load 1/255 Encapsulation ARPA, loopback not set, keepalive set (10 sec) Routing metric ARP link type: ARPA, ARP Timeout 04: 00 ARP cache entries timer Data information Last input never, output 01: 05: 35, output hang never encapsulation (later) (Ethernet-II) 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> Rick Graziani graziani@cabrillo. edu 13

Where is the MAC Address? Router>show interface serial 0 Serial 0 is administratively down, line protocol is down Hardware is HD 64570 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 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 14

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

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

show ip interface command Router# show ip interface brief Interface Ethernet 0 Serial 0 IP-Address 131. 108. 1. 11 198. 135. 2. 49 OK? YES Method manual Status up administratively down Protocol up down What is wrong here? The administrator has either done a “shutdown” on the interface or has forgotten to do a “no shutdown”. • • 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. Rick Graziani graziani@cabrillo. edu 17

Configuring a serial interface Lab Real world • • 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 Rick Graziani graziani@cabrillo. edu 18

Configuring a serial interface Router. A DTE cable Router. B DCE cable Router. B(config)#inter serial 1 Router. B(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 Router. B(config-if)#clock rate 64000 Router. B(config-if)# Rick Graziani graziani@cabrillo. edu 19

Configuring a serial interface DTE Cable DCE Cable How can you tell which end is the DTE and which end is the DCE? n Look at the label on the cable. n 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 20

Configuring a serial interface Router. A DTE cable Router. B DCE cable Router. A#show controllers serial 0 HD unit 0, idb = 0 x. ECA 4 C, driver structure at 0 x. F 1 EC 8 buffer size 1524 HD unit 0, V. 35 DTE cable cpb = 0 x 62, eda = 0 x 403 C, cda = 0 x 4050 RX ring with 16 entries at 0 x 624000 00 bd_ptr=0 x 4000 pak=0 x 0 F 5704 ds=0 x 62 FFB 8 status=80 pak_size=22 This is one of few commands where there must be a space between the interface type and the port. Router. B#show controllers serial 0 buffer size 1524 HD unit 0, V. 35 DCE cable, clockrate 64000 cpb = 0 x 62, eda = 0 x 408 C, cda = 0 x 40 A 0 RX ring with 16 entries at 0 x 624000 00 bd_ptr=0 x 4000 pak=0 x 0 F 2 F 04 ds=0 x 627908 status=80 pak_size=22 How can you tell which end is the DTE and which end is the DCE? n Use the show controllers command! n 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 21

Configuring a serial interface This end up! (The wider end is up. ) • • 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! Rick Graziani graziani@cabrillo. edu 22

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

Executing adds, moves, and changes Router#show startup-config %% Non-volatile configuration memory is not present No startup-config file in NVRAM 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 Ethernet 0 no ip address no ip directed-broadcast shutdown ! interface Serial 0 no ip address no ip directed-broadcast shutdown Rick Graziani graziani@cabrillo. edu Default running-config file, created in RAM 24

Executing adds, moves, and changes 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 Ethernet 0 no ip address no ip directed-broadcast shutdown • • The running-config 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. Rick Graziani graziani@cabrillo. edu 25

copy running-config startup-config During bootup running-config RAM startup-config Router# 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 runningconfig 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 Rick Graziani graziani@cabrillo. edu startup-config 26

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 Ethernet 0 no ip address no ip directed-broadcast shutdown ! Rick Graziani graziani@cabrillo. edu The startup-config file now identical to running-config and the router will also have these changes if the router reboots. 27

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 **** Incorrect file name! Flash load helper v 1. 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. Press <control> C Router# 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 • 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# Rick Graziani graziani@cabrillo. edu Incorrect file name! Press <control> C 29

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 30

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

Configuring Interfaces Router(config-if)#exit Router(config)#interface serial 0 Router(config-if)#ip add 172. 16. 10. 1 255. 0 Router(config-if)#clock rate 64000 (only if DCE) Router(config-if)#no shutdown Rick Graziani graziani@cabrillo. edu 32

Finishing the Configuration Rick Graziani graziani@cabrillo. edu 33

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 34

Interface descriptions Router. B#show inter e 0 Serial 0 is up, line protocol is up Hardware is HD 64570 Description: Engineering LAN, Bldg. 18 Internet address is 10. 1. 1. 1/24 Rick Graziani graziani@cabrillo. edu 35

Interface descriptions Gateway(config)#inter e 0 Gateway(config-if)#description LAN interface for Marketing Gateway(config-if)#end Gateway#show run Building configuration. . . <text omitted> ! interface Ethernet 0 description LAN interface for Marketing no ip address no ip directed-broadcast shutdown <text omitted> Gateway#show interface ethernet 0 Ethernet 0 is administratively down, line protocol is down Hardware is Lance, address is 0000. 0 c 34. 9 ebb ( bia 0000. 0 c 34. 9 ebb) 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 <text omitted> Gateway#copy run start Don’t forget this or next time router Destination filename [startup- config]? reboots these changes will be lost! Building configuration. . . Gateway# Rick Graziani graziani@cabrillo. edu 36

Configuring interface description Rick Graziani graziani@cabrillo. edu 37

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

Login banners and Configuring messageof-the-day (MOTD) Router(config)#hostname Gateway(config)# MOTD Gateway(config)#banner motd # Enter TEXT message. End with the character '#'. Warning! Stay away! # Gateway(config)#end Gateway#exit Press RETURN to get started. Prompt changes (Message Of The Day) 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 Rick Graziani graziani@cabrillo. edu Delimiter always shows as “^C” 39

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 40

Host name resolution Configuring Multiple IP Addresses Router(config)# ip host Santa. Cruz 172. 16. 32. 1 192. 168. 53. 1 • • • 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. Rick Graziani graziani@cabrillo. edu 41

Configuring host tables Rick Graziani graziani@cabrillo. edu 42

Router(config)# ip domain-lookup Router#wreh Translating "wreh". . . domain server (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 • • • 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, 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. Rick Graziani graziani@cabrillo. edu 43

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 44

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 45

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 46

Copying, editing, and pasting configurations running-config RAM IOS (running) startup-config IOS 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 47

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

TFTP Software and Servers Router# copy flash tftp • • • 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). Rick Graziani graziani@cabrillo. edu 49

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 50

TFTP Software and Servers • • Just double click on the shortcut… Remember, TFTP is “Trivial” FTP: – No authentication – No login – No choice for directory – Uses UDP and verified via a TFTP checksum (not TCP ACKs) Rick Graziani graziani@cabrillo. edu 51

Summary (1/2) The router has several modes: • User EXEC mode • Privileged EXEC mode • Global configuration mode • Other configuration modes The command-line interface may be used to make changes to the configuration: • Setting the hostname • Setting passwords • Configuring interfaces • Modifying configurations • Showing configurations Rick Graziani graziani@cabrillo. edu 52

Summary (2/2) An understanding of the following key points should have been achieved: • Configuration standards are key elements in the success of any organization maintaining an efficient network. • Interface descriptions can include important information to help network administrators understand troubleshoot their networks. • Login banners and messages-of-the-day provide users with information upon login to the router. • Host name resolutions translate names to IP addresses to allow the router to quickly convert names to addresses. • Configuration backup and documentation is extremely important to keep a network operating smoothly. Rick Graziani graziani@cabrillo. edu 53