Troubleshooting Dial-on-Demand Routing (DDR) Issues in IGRP

Dial-on-demand routing is very common when the ISDN or similar dialup links are used as a backup link. When the primary link goes down, this backup link comes up. IGRP starts sending and receiving updates on this link as long as the primary link is down. Two ways exist for using the dialup links as a backup for the primary link: • Using the backup interface command • Using floating static routes with a dialer list that defines interesting traffic The first m..

Configuring AppleTalk Addresses

In this section, we examine the configuration of AppleTalk addresses on LAN and WAN interfaces. Before you assign addresses, you should develop a sensible, overall addressing scheme for your network. A few rules govern the addressing. The following are tips to help guide you: • Single network numbers should appear on only one LAN or WAN segment. • Cable-ranges should appear on only one LAN or WAN segment, and no cable-range or portion of a cable-range should b..

Catalyst Configuration File Management

For complete system recovery, make sure that you have a copy of each Catalyst's configuration file stored somewhere other than on the Catalyst itself. If anything happens to the Catalyst Supervisor module, you might not be able to recover the configuration file. It is a crime to have to rebuild the entire configuration file from scratch during a system outage when it is easy to create a backup on a network accessible machine. Through TFTP, you can store your configuration fi..

Debugging Dial Backup

The most common reasons for failed dial backup calls are incorrect dial strings and PPP authentication problems. You can easily diagnose both of these problems with this command: Router1#debug ppp authentication Here is another useful command for diagnosing problems with dialer configurations: Router1#debug dialer When you use CHAP authentication with PPP, as we have done throughout this chapter, it is relatively easy to debug most common problems. We like to use the debu..

Local Area Mobility

In this example, the roaming device will have a statically configured address in the 192.168.10.0/24 range. We have to configure the home router to use Proxy ARP for mobile nodes, allowing other locally connected devices in the same range to communicate transparently with the roaming device: RouterHome#configure terminal Enter configuration commands, one per line.  End with CNTL/Z. RouterHome(config)#interface FastEthernet0/0 RouterHome(config-if)#ip address 192.168...