Preventing Suboptimal Routes by Using Route Tags
Another method of preventing suboptimal routing on the redistributing routers is to simply filter theproblematic routes. Using subnet 10.1.2.0/24 as an example again, R3 could use an incomingdistribute-list command to filter the OSPF route to 10.1.2.0/24, allowing R3 to use its RIP route to10.1.2.0/24. R1 would need to perform similar route filtering as well to prevent its suboptimal route. Performing simple route filtering based on IP subnet number works, but the redistribu..
Establishing Adjacencies on a Point-to-Point Link
When point-to-point links are used, adjacency occurs after a Hello packet has been received. Next, each side sends a CSNP. The CSNP is a list of all the links held in the linkstate database, which triggers a synchronization of the link-state database on each machine. Periodic Hellos maintain the adjacency. If a router does not hear a Hello within the Hello holdtime, the neighbor is declared dead and the database is purged of any entries associated with the router. Cisc..
Unequal-Cost Load Balancing in IGRP
IGRP and RIP provide the capability to install up to six parallel equal-cost paths for load balancing. IGRP has an added feature that RIP does not have—the capability to do unequal-cost load balancing, the capability to load-balance traffic over multiple paths that do not have the same metric to the destination. The advantage of this feature is that it offers the flexibility of load balancing, thus making more efficient use of the link. IGRP uses the variance command to per..
When you first receive a Catalyst from Cisco, it has no password set. In other words, the password is <ENTER> to enter both the EXEC and privilege modes. Your first task as a conscientious network administrator should be to change the passwords to the unit. This helps to prevent unauthorized children in adult form from modifying the Catalyst and disrupting your network. Example 4-11 shows a Catalyst session where the user changes the EXEC and enable passwords. The user ..
Here are some useful commands for looking at the status of a dial backup link. For dial backup that uses the floating static or dialer watch type configurations, you can use the show dialer command: Router1#show dialer For dial configurations that use the backup interface configuration, you can use the show backup command: Router1#show backup And, for backup configurations that use ISDN, you can get some additional information from the show isdn status, show isdn active, ..
