OSPF Series 11: Everything on Redistribution: Part 2- Redistribution into OSPF, Pitfall of Redistribution (Administrative Distance, Route Feedback)

Everything on Redistribution: Part 2- Redistribution into OSPF, Pitfall of Redistribution (Administrative Distance, Route Feedback)

 

Redistributing into OSPF

OSPF is a standardized Link-State routing protocol that uses cost (based on bandwidth) as its link-state metric. An OSPF router performing redistribution automatically becomes an ASBR

OSPF Series 10: Everything on Redistribution: Part 1- Basics, RIP, IGRP, EIGRP, Static and Connected

Everything on Redistribution- Basics, RIP, IGRP, EIGRP, Static and Connected

Route Redistribution Basics

It is preferable to employ a single routing protocol in an internetwork environment, for simplicity and ease of management. Unfortunately, this is not always possible, making multi-protocol environments common.

Route Redistribution allows routes

OSPF Series 9: Route Filtering and Route-Maps

Prefix-Lists

Prefix-lists are used to match routes as opposed to traffic. Two things are matched:

• The prefix (the network itself)

• The prefix-length

OSPF Series 8: Prefix Lists

Prefix Lists

Example 1)

access-list 1 permit 1.2.3.0 0.0.0.255

ip prefix-list LIST permit 0.0.0.0/0 le 32

This means:

Check the first 0 bits of the prefix 0.0.0.0 The subnet mask must be less than or equal to 32