FAQ on Lab Experiments

Contents:

Lab 4, Part 4: Count to Infinity Problem.
Lab 6, Part 1 and Part 5: Running brctl on Linux PCs.

Note: Also see the FAQ on lab equipment and the list of errata. Report new problems, if possible with solutions, by sending email to jorg@cs.virginia.edu.

1. Lab 4, Part 4: Count to Infinity Problem.

Problem: Reproducing the count-to-infinity problem on Cisco 2621's running IOS "12.2(5d) Release Software fc1". The problem lies in the fact that flash-update-threshold seems to do absolutely nothing with regards to disabling triggered updates. As soon as a router with "triggered updating disabled" receives a new message, it immediately (within 2-3 seconds) redistributes this
information to the other routers on its other connected link.

Response (for Cisco 2611 with IOS v12.0). The problem may be that the flash update does not show as disabled, probably, due to the version of IOS. Try this interface command"no ip rip triggered" to disable triggered updates. This command is introduced in running Cisco IOS Release 12.0(1)T. Also, make sure the holddown timer is set to 0.

(Source: Sun Woo Kim, UC Irvine)

2. Lab 6, Part 1 and Part 5: Running brctl on Linux PCs.

This problem is equipment dependent. Click here.

(END)