Cisco Systems Router 1800 Series User Manual

							
 
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Chapter 1      Basi c Router Configuration
  Configuring Basic Parameters
Configure the Wireless Interface
The wireless interface enables connection to the router through a wireless LAN connection. For more 
information about configuring a wireless connection, see 
Chapter 9, “Configuring a Wireless LAN 
Connection” and the Cisco Access Router Wireless Configuration Guide.
Configuring a Loopback Interface
The loopback interface acts as a  placeholder for the static IP address and provides default routing 
information.
For complete information on the loopback commands, see the Cisco IOS Release 12.3 
documentation
 set. 
Perform these steps to conf igure a loopback interface:
CommandPurpose
Step 1interface type number
Example:
Router(config)#  interface Loopback 0
Router(config-int)# 
Enters interface configuration mode.
Step 2ip address ip-address mask
Example:
Router(config-int)#  ip address 10.108.1.1 
255.255.255.0
Router(config-int)# 
Sets the IP address and subnet mask for the 
loopback interface.
Step 3exit
Example:
Router(config-int)#  exitRouter(config)# 
Exits configuration mode for the loopback 
interface and returns to global configuration 
mode.
Configuration Example
The loopback interface in this sample configuratio n is used to support Network Address Translation 
(NAT) on the virtual-template interface. This configuration example shows the loopback interface 
configured on the Fast Ethernet inte rface with an IP address of 200.200.100.1/24, which acts as a static 
IP address. The loopback interface po ints back to virtual-template1, which has a negotiated IP address. 
!interface loopback 0
ip address 200.200.100.1 255.255.255.0 ( static IP address)
ip nat outside!
interface Virtual-Template1
ip unnumbered loopback0no ip directed-broadcast
ip nat outside 
						

							 
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Chapter 1      Basic Router Configuration
  Configuring Basic Parameters
Verifying Your Configuration
To verify that you have properly configured the loopback interface, enter the show interface loopback 
command. You should see verification output similar to the following example.
Router# show interface loopback 0
Loopback0 is up, line protocol is up 
  Hardware is Loopback  Internet address is 200.200.100.1/24
  MTU 1514 bytes, BW 8000000 Kbit, DLY 5000 usec, 
     reliability 255/255, txload 1/255, rxload 1/255  Encapsulation LOOPBACK, loopback not set
  Last input never, output never, output hang never
  Last clearing of show interface counters never  Queueing strategy: fifo
  Output queue 0/0, 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 packets output, 0 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets     0 output buffer failures, 0 output buffers swapped out
Another way to verify the loopback interface is to ping it:
Router# ping 200.200.100.1 
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 200.200.100.1, timeout is 2 seconds:!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms
Configuring Command-Line Access to the Router
Perform these steps to configure parameters to control access to the router, beginning in global 
configuration mode:
CommandPurpose
Step 1line [aux | console | tty | vty] line-number 
Example:
Router(config)# line console 0Router(config)# 
Enters line configuration mode, and specifies the 
type of line.
This example specifies a console terminal for 
access.
Step 2password password
Example:
Router(config)# password 5dr4Hepw3
Router(config)# 
Specifies a unique password for the console 
terminal line. 
						

							 
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Chapter 1      Basic Router Configuration
  Configuring Basic Parameters
For complete information about the command line commands, see the Cisco IOS Release 12.3 
documentation set. 
Step 3login
Example:
Router(config)# loginRouter(config)# 
Enables password checking at terminal session 
login.
Step 4exec-timeout minutes [seconds]
Example:
Router(config)# exec-timeout 5 30
Router(config)# 
Sets the interval that the EXEC command 
interpreter waits until user input is detected. The 
default is 10 minutes. Optionally, add seconds to 
the interval value.
This example shows a timeout of 5 minutes and 
30
 seconds. Entering a timeout of 0 0 specifies 
never to time out.
Step 5line [aux | console | tty | vty] line-number 
Example:
Router(config)# line vty 0 4
Router(config)# 
Specifies a virtual terminal for remote console 
access.
Step 6password password
Example:
Router(config)# password aldf2ad1
Router(config)# 
Specifies a unique password for the virtual 
terminal line.
Step 7login
Example:
Router(config)# login
Router(config)# 
Enables password checking at the virtual terminal 
session login.
Step 8end
Example:
Router(config)# endRouter# 
Exits line configuration mode, and returns to 
privileged EXEC mode.
Command Purpose 
						

							
 
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Chapter 1      Basic Router Configuration
  Configuring Static Routes
Configuration Example
The following configuration shows the command-line access commands.
You do not need to input the commands marked “default.” These commands appear automatically in the 
configuration file generated when you use the  show running-config command.
!line con 0
exec-timeout 10 0
password 4youreyesonlylogin
transport input none  (default)
stopbits 1 (default)line vty 0 4
password secret
login!
Configuring Static Routes
Static routes provide fixed routing paths through the network. They are manually configured on the 
router. If the network topology changes, the static route must be updated with a new route. Static routes 
are private routes, unless they are redistributed by a routing protocol. Configuring static routes on the 
Cisco
 1800 series routers is optional.
Perform these steps to configure static routes, beginning in global configuration mode:
CommandPurpose
Step 1ip route prefix mask  {ip-address  | interface-type  
interface-number  [ip-address ]} 
Example:
Router(config)#  ip route 192.168.1.0 
255.255.0.0 10.10.10.2
Router(config)# 
Specifies the static route for the IP packets.
For details about this command and additional 
parameters that can be set, see the
 Cisco IOS IP 
Command Reference, Volume 2 of 4: Routing 
Protocols.
Step 2end
Example:
Router(config)#  end
Router# 
Exits router configuration mode, and enters 
privileged EXEC mode.
For complete information on the static routing commands, see the Cisco IOS Release 12.3 
documentation set. For more general information on static routing, see 
Appendix B, “Concepts.” 
						

							 
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Chapter 1      Basic Router Configuration
  Configuring Dynamic Routes
Configuration Example
In the following configuration example, the static route sends out all IP packets with a destination IP 
address of 192.168.1.0 and a subnet mask of 255.255.255.0 on the Fast Ethernet interface to another 
device with an IP address of 10.10.10.2. Specifically, the packets are sent to the configured PVC.
You do not need to enter the commands marked “(default).” These commands appear automatically in 
the configuration file generated when you use the show running-config command.
!ip classless (default)
ip route 192.168.1.0 255.255.255.0 10.10.10.2!
Verifying Your Configuration
To verify that you have properly configured static routing, enter the show ip route command and look 
for static routes signified by the “S.” 
You should see verification output similar to the following example.
Router# show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
     10.0.0.0/24 is subnetted, 1 subnetsC       10.108.1.0 is directly connected, Loopback0
S* 0.0.0.0/0 is directly connected, FastEthernet0
Configuring Dynamic Routes
In dynamic routing, the network protocol adjusts the path automatically, based on network traffic or 
topology. Changes in dynamic routes are shared with other routers in the network.
The Cisco routers can use IP routing protocols, such as Routing Information Protocol (RIP) or Enhanced 
Interior Gateway Routing Protocol (EIGRP), to learn routes dynamically. You can configure either of 
these routing protocols on your router. 
						

							
 
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Chapter 1      Basic Router Configuration
  Configuring Dynamic Routes
Configuring RIP
Perform these steps to configure the RIP routing protocol on the router, beginning in global 
configuration mode:
CommandTa s k
Step 1router rip
Example:
Router>  configure terminal
Router(config)#  router rip
Router(config-router)# 
Enters router configuration mode, and enables RIP 
on the router.
Step 2version {1  | 2 }
Example:
Router(config-router)#  version 2
Router(config-router)# 
Specifies use of RIP version 1 or 2.
Step 3network ip-address
Example:
Router(config-router)#  network 192.168.1.1
Router(config-router)# network 10.10.7.1Router(config-router)# 
Specifies a list of networks on which RIP is to be 
applied, using the address of the network of 
directly connected networks.
Step 4no auto-summary
Example:
Router(config-router)# no auto-summary
Router(config-router)# 
Disables automatic summarization of subnet routes 
into network-level routes. This allows subprefix 
routing information to pass across classful network 
boundaries.
Step 5end
Example:
Router(config-router)# end
Router# 
Exits router configuration mode, and enters 
privileged EXEC mode.
For complete information on the dynamic routing commands, see the Cisco IOS Release 12.3 
documentation set. For more general information on RIP, see 
Appendix B, “Concepts.”  
						

							 
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Chapter 1      Basic Router Configuration
  Configuring Enhanced IGRP
Configuration Example
The following configuration example shows RIP version 2 enabled in IP network 10.0.0.0 and 
192.168.1.0.
Execute the show running-config command from privileged EXEC mode to see this configuration.
!router rip
 version 2
 network 10.0.0.0 network 192.168.1.0
 no auto-summary
!
Verifying Your Configuration
To verify that you have properly configured RIP, enter the show ip route command and look for RIP 
routes signified by “R.” You should see a verification output like the example shown below. 
Router# show ip routeCodes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
     10.0.0.0/24 is subnetted, 1 subnets
C       10.108.1.0 is directly connected, Loopback0
R    3.0.0.0/8 [120/1] via 2.2.2.1, 00:00:02, Ethernet0/0
Configuring Enhanced IGRP
Perform these steps to configure Enhanced IGRP (EIGRP), beginning in global configuration mode:
CommandPurpose
Step 1router eigrp as-number
Example:
Router(config)# router eigrp 109Router(config)# 
Enters router configuration mode, and enables 
EIGRP on the router. The autonomous-system 
number identifies the route to other EIGRP routers 
and is used to tag the EIGRP information. 
						

							 
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Chapter 1      Basic Router Configuration
  Configuring Enhanced IGRP
For complete information on the IP EIGRP commands, see the Cisco IOS Release 12.3 documentation 
set. For more general information on EIGRP concepts, see 
Appendix B, “Concepts.”
Configuration Example
The following configuration example shows the EIGRP routing protocol enabled in IP networks 
192.145.1.0 and 10.10.12.115. The EIGRP autonomous system number is assigned as 109.
Execute the show running-config command from privileged EXEC mode to see this configuration.
!router eigrp 109
network 192.145.1.0
network 10.10.12.115!
Verifying Your Configuration
To verify that you have properly configured IP EIGRP, enter the show ip route command, and look for 
EIGRP routes indicated by “D.” You should see verification output similar to the following example.
Router# show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
     10.0.0.0/24 is subnetted, 1 subnets
C       10.108.1.0 is directly connected, Loopback0
D    3.0.0.0/8 [90/409600] via 2.2.2.1, 00:00:02, Ethernet0/0
Step 2network ip-address
Example:
Router(config)# network 192.145.1.0Router(config)# network 10.10.12.115
Router(config)# 
Specifies a list of networks on which EIGRP is to 
be applied, using the IP address of the network of 
directly connected networks.
Step 3end
Example:
Router(config-router)# endRouter# 
Exits router configuration mode, and enters 
privileged EXEC mode.
Command Purpose 
						

							PART 2
Configuring Your Router for Ethernet and 
DSL Access