思科 路由器的配置 CISCO ROUTER 1700 CONFIGURING

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Configuring Global Parameters

Follow these steps to configure the router for global parameters.









Command



Task




Step 1  



configure terminal



Enter configuration mode.





Step 2  



service timestamps debug datetime msec



Configure the router to show the date and time of all debug messages.

This command is optional, but it is recommended if you use debug commands to troubleshoot your configuration.





Step 3  



service timestamps log datetime msec



Configure the router to show the date and time of all log messages.

This command is optional, but it is recommended if you use the verification steps described in this guide. This feature is enabled for all the command output examples shown in this guide.





Step 4  



ip subnet-zero



Configure the router to use subnet zero for interface addresses and routing updates.





Step 5  



no ip domain-lookup



Disable the IP Domain Name System (DNS)-based host name-to-address translation on the router.





Step 6  



ipx routing 0000.0caa.1111



Enable IPX routing, and configure the router with an IPX address.





Configuring Security

Follow these steps to configure the router with security measures.









Command



Task




Step 1  



enable password



Specify a password to prevent unauthorized access to the router.





Step 2  



hostname Router



Configure the router with a host name, which is used in prompts and default configuration filenames.

For PPP authentication, the host name entered with this command must match the username of the central-site router.





Configuring the Fast Ethernet Interface

Follow these steps to configure the Fast Ethernet interface, which connects your router to the local network.









Command



Task




Step 1  



interface fastethernet0



Enter configuration mode for the Fast Ethernet interface.





Step 2  



ip address 10.1.1.1 255.0.0.0



Configure this interface with an IP address and a subnet mask. This interface must have an IP address assigned in order for the serial interface to be configured for IP unnumbered routing.





Step 3  



ipx network 100 encapsulation sap



Enable IPX routing on this interface, assign the IPX network number, and configure the interface for IPX SAP encapsulation.





Step 4  



ipx network 100 encapsulation novell-ether secondary



Configure a secondary IPX network that uses the default NetWare encapsulation.





Step 5  



no shutdown



Enable the interface and the configuration changes you have just made on the interface.





Step 6  



exit



Exit configuration mode for this interface.





Configuring the Serial Interface

Follow these steps to configure the serial interface, which connects your router to the central-site router.









Command



Task




Step 1  



interface serial0



Enter configuration mode for the serial interface.





Step 2  



description leased line to headquarters



Add a description of this interface to help you remember what is attached to it.





Step 3  



ip unnumbered FastEth0



Enable IP routing on this interface without assigning an IP address.





Step 4  



ipx network AAAA



Enable IPX routing on this interface, and assign an IPX network number.





Step 5  



encapsulation PPP



Configure this interface for PPP encapsulation.





Step 6  



no shutdown



Enable this interface and the configuration changes you have just made on the interface.





Step 7  



exit



Exit configuration mode for this interface.





Configuring Dynamic Routing Parameters

Follow these steps to configure some dynamic routing parameters.









Command



Task




Step 1  



router rip



Enable RIP routing on the router, and enter router configuration mode.





Step 2  



version 2



Specify the router to use RIP version 2.





Step 3  



network 10.0.0.0



Enable Enhanced Interior Gateway Routing Protocol (EIGRP) for this network.





Step 4  



no auto-summary



Disable automatic summarization of subnet routes into network-level routes.





Step 5  



ip classless



Configure the router to forward packets addressed to a subnet of a network with no network default route.





Step 6  



exit



Exit router configuration mode.





Configuring Command-Line Access to the Router

Follow these steps to configure parameters that control access to the router.









Command



Task




Step 1  



line console 0



Specify the console terminal line, and enter line configuration mode.





Step 2  



exec-timeout 5



Set the interval that the EXEC command interpreter waits until user input is detected.





Step 3  



line vty 0 4



Specify a virtual terminal for remote console access.





Step 4  



password



Specify a password on the line.





Step 5  



login



Enable password checking at terminal session login.





Step 6  



end



Exit configuration mode.





Verifying Your Configuration

You can verify your configuration by checking the serial interface configuration:


Step 1 http://www.cisco.com/en/US/i/templates/blank.gifFrom privileged EXEC command mode, enter the show interface serial0 command. You should see output similar to the following:



Router# show interface ser0



Serial0 is up, line protocol is up



  Hardware is PowerQUICC Serial



  Description: leased line to headquarters



  Interface is unnumbered.  Using address of FastEthernet0 (10.1.1.1)



  MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load
1/255



  Encapsulation PPP, loopback not set, keepalive set (10 sec)



  LCP Closed



.



.



.






Step 2 http://www.cisco.com/en/US/i/templates/blank.gifConfirm that the "Serial0 is up, line protocol is up" message appears, as shown in the command output example.

Step 3 http://www.cisco.com/en/US/i/templates/blank.gifProceed as appropriate:

•http://www.cisco.com/en/US/i/templates/blank.gifIf you see the "Serial0 is up, line protocol is up" message shown in the example command output, continue configuration by reentering global configuration mode.

•http://www.cisco.com/en/US/i/templates/blank.gifIf you see one of the following messages instead of the "Serial0 is up, line protocol is up" message, see the "Troubleshooting Problems with Leased Lines" section for possible causes of the message and suggested actions:

–http://www.cisco.com/en/US/i/templates/blank.gifSerial0 is down, line protocol is down.

–http://www.cisco.com/en/US/i/templates/blank.gifSerial0 is up, line protocol is down.

–http://www.cisco.com/en/US/i/templates/blank.gifSerial0 is up, line protocol is up (looped).

–http://www.cisco.com/en/US/i/templates/blank.gifSerial0 is administratively down, line protocol is up.


Troubleshooting Problems with Leased Lines

Table 6-1 describes some common problems with leased lines, possible causes, and suggested actions for solving the problems. The table uses Serial 0 port as the location of the problems.





Table 6-1 Possible Causes of and Suggested Actions for Solving Problems with Leased Lines  





Line State



Possible Cause



Suggested Actions




Serial0 is down, line protocol is down.



The router is not sensing a Carrier Detect (CD) signal as a result of one of the following:

•http://www.cisco.com/en/US/i/templates/blank.gifTelephone company problem, such as the line is down or not connected to the data service unit / channel service unit (DSU/CSU).

•http://www.cisco.com/en/US/i/templates/blank.gifFaulty or incorrect cabling of the router.

•http://www.cisco.com/en/US/i/templates/blank.gifLocal DSU/CSU hardware failure.

•http://www.cisco.com/en/US/i/templates/blank.gifLocal router hardware failure.



The following are some steps you can take to isolate the problem:

•http://www.cisco.com/en/US/i/templates/blank.gifCheck the LEDs on the external DSU/CSU for CD activity.

•http://www.cisco.com/en/US/i/templates/blank.gifRefer to the Hardware Installation Guide to confirm that your router is correctly installed, using the appropriate cables.

•http://www.cisco.com/en/US/i/templates/blank.gifContact the telephone company to determine if the leased line is down or not connected.

•http://www.cisco.com/en/US/i/templates/blank.gifConnect the leased line to another port, if possible. If the connection comes up, there is a hardware failure on the Serial 0 port. Contact your Cisco reseller.





Serial0 is up, line protocol is down.



Possible causes for this line state are

•http://www.cisco.com/en/US/i/templates/blank.gifLocal or remote router misconfigured.

•http://www.cisco.com/en/US/i/templates/blank.gifThe remote router is not sending keepalive packets.

•http://www.cisco.com/en/US/i/templates/blank.gifProblem with the leased line.

•http://www.cisco.com/en/US/i/templates/blank.gifThe serial clock transmit external is not set on the DSU/CSU.

•http://www.cisco.com/en/US/i/templates/blank.gifLocal or remote DSU/CSU hardware failure.

•http://www.cisco.com/en/US/i/templates/blank.gifRouter hardware failure.



The following are some steps you can take to isolate the problem:

•http://www.cisco.com/en/US/i/templates/blank.gifPerform DSU/CSU loopback tests. During local loopback, enter the show interface ser0 command. If the line protocol is shown as up, there might be a problem with the telephone company, or the remote router might be down.

•http://www.cisco.com/en/US/i/templates/blank.gifRefer to the Hardware Installation Guide to confirm that your router is correctly installed, using the appropriate cables.

•http://www.cisco.com/en/US/i/templates/blank.gifConnect the leased line to another port, if possible. If the connection comes up, there is a hardware failure on the Serial 0 port. Contact your Cisco reseller.





Serial0 is up, line protocol is up (looped).



The possible cause is that a loop exists in the circuit. The sequence number in the keepalive packet changes to a random number when a loop is first detected. If the same random number is returned over the line, a loop exists.



The following are some steps you can take to isolate the problem:

•http://www.cisco.com/en/US/i/templates/blank.gifUse the write terminal privileged EXEC command to display any instances of the loopback command. If the router has been configured with the loopback command, enter the no loopback command to remove the loop.

•http://www.cisco.com/en/US/i/templates/blank.gifCheck to see whether the DSU/CSU is configured in manual loopback mode. If it is, disable manual loopback.

•http://www.cisco.com/en/US/i/templates/blank.gifReset the DSU/CSU.

•http://www.cisco.com/en/US/i/templates/blank.gifIf you are unable to isolate the problem, contact the telephone company for help with troubleshooting.





Serial0 is administratively down, line protocol is up.



The possible causes for this state are

•http://www.cisco.com/en/US/i/templates/blank.gifThe serial interface has been disabled with the shutdown interface configuration command.

•http://www.cisco.com/en/US/i/templates/blank.gifDifferent interfaces on the router are using the same IP address.



The following are some steps you can take to isolate the problem:

•http://www.cisco.com/en/US/i/templates/blank.gifUse the show configuration privileged EXEC command to display the serial port configuration. If "shutdown" is displayed after "interface Serial0," use the no shutdown interface configuration command to enable the interface.

•http://www.cisco.com/en/US/i/templates/blank.gifUse the show interface privileged EXEC command to display the IP addresses for all router interfaces. Use the ip address interface configuration command to assign unique IP addresses to the router interfaces.