The order of preference for OSPF routes are as follows:
intra-area routes, O
inter-area routes O IA
external routes type 1, O E1
external routes type 2, O E2
I'm not completely sure about your areas, but it looks like you want traffic
from routerB to traverse area1 to routerA in area 0.
If the T1s could be in area 1 rather than area 0, as they probably should be
based on bandwidth, your problem should be solved.
-----Original Message-----
From: jlewis@lewis.org [mailto:jlewis@lewis.org]
Sent: Monday, June 11, 2001 3:46 PM
To: cisco-nsp@puck.nether.net
Subject: [nsp] how to fool the SPF in OSPF?
Given a network such as:
-----------------------------------
| routerA------T3------routerC |
|___ | _________________ | __| area 0
| | | | | |
| T1s | | T3 |
| | / | | |
\ | / /-------------\ \ | /
routerB-----100bt------routerD
\-------------/
area 1
how do I get around the T1's connecting A and B being the shortest path
and get B to send traffic to A via D unless one of the T3's above is down?
I can't just use static routes on B, because it won't know if a T3 is
down. I've tried playing with "ip ospf cost" on the T1's but B still
prefers them.
-- ---------------------------------------------------------------------- Jon Lewis *jlewis@lewis.org*| I route System Administrator | therefore you are Atlantic Net | _________ http://www.lewis.org/~jlewis/pgp for PGP public key_________
This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:12:41 EDT