Offset List

[navneet_78]

What are Offset lists and distribute lists used for? And how are they different from each other?

[gopal_4476]

Hi Naveen,

distribut list is used for filtering the routing updated from routing protocol in and out of your network.

offset list is used for incresing the metric of incoming and outgoing routing updated.

hope this would clear your doubts.

Regards

Gopal

[navneet_78]

Thnx for the reply gopal.

In what scenario would you use offset lists? I mean by increasing the metric how will it help?

Regards

Navneet

[dwyerr]

Hello,

Since RIP uses hop count for a metric links of different bandwidths appear to be the same. If you had two links, T1 and FE for example, each one hop away the router would load share on these links.

Offset list would allow you to increase the hop count on the slower link , preferring the better path.

Just one example ...though there are plenty of jams that this could get you out of I am sure :-)

-Rob

[Richard Burts]

Another example is this: at a site where I have done a lot of consulting we normally have two paths from remote offices to the HQ. We run EIGRP as the routing protocol. Normally EIGRP would consider both paths equal and would load share. To make the traffic deterministic we want a preferred path and a backup path. We apply an offset list on one path to make the metric higher and make that path the backup path. This works very well.

HTH

Rick

[navneet_78]

Thnx for the Reply Rick.

Also, do we only apply Distribute list outside any interface? Can we do it for inside too??

Regards

Navneet

[sundar.palaniappan]

Navneet,

You can use distribute list in both directions - in or out an interface.

Distribute list filters routing updates. Offset lists increments/decrements routing metrics.

Pls. rate all helpful posts.

HTH,

Sundar