Network Warrior, 2nd Edition

Redistributing into EIGRP

EIGRP was designed to automatically redistribute IGRP routes from the same ASN. You can disable this behavior with the no redistribute igrp autonomous-system command:

router eigrp 100
 no redistribute igrp 100

You redistribute routes into EIGRP in the same way as you do with RIP. It only looks harder because the metric in EIGRP is more complicated than that in RIP; whereas RIP only uses hop count as a metric, EIGRP uses the combined bandwidth and delay values from all the links in the path. In fact, EIGRP uses more than just these two measurements, but, by default, the other metrics are disabled. However, with redistribution, you must specify them, so let’s take a look at what they should be.

As with RIP, you can use the default-metric command to specify the metric of redistributed routes, or you can specify the metric on each redistribute command line. Here are the arguments required for the default-metric command in EIGRP, and the allowed ranges of values:

• Bandwidth in Kbps: 1–4,294,967,295

• Delay in 10-microsecond units: 0–4,294,967,295

• Reliability metric, where 255 is 100 percent reliable: 0–255

• Effective bandwidth metric (loading), where 255 is 100 percent loaded: 1–255

• Maximum Transmission Unit (MTU) metric of the path: 1–4,294,967,295

How you configure these values will depend largely on your needs at the time. Remember that redistributed routes are external routes, so they will always have a higher administrative distance than internal routes in EIGRP. Such ...