From: Bill Dicks (wdicks@xxxxxxxxxxxxxxxxxx)
Date: Thu Jul 20 2000 - 23:18:17 GMT-3
A few problems/issues:
1. On the EBGP peer, use the physical link's address: 192.168.1.1and
172.16.1.1, not your loopback. You use loopbacks for IBGP peers because if
done correctly, the other router will have multiple paths to the loopback
via IGPs. That's not the case with EBGP. So use the IP addresses on the
physical links to peer with EBGP.
2. Did the ISP's actually give you private addresses on the serial line???
Also, where are these 216.x.x.x networks coming from?
3. If you did want to peer with a loopback over ebgp, you must make sure the
ISPs have EBGP-multihop set on their routers. Also, will the ISP's actually
peer to 10.x.x.x address? The one's I've run into won't.
4. There's currently nothing stopping one ISP from routing its traffic
through your AS to the other ISP. Setup a filter to only send routes that
originate in your AS (match the as-path list of ^$)
Hope this helps,
Bill
-----Original Message-----
From: jaarons-hotmail [mailto:jaarons@hotmail.com]
Sent: Thursday, July 20, 2000 8:28 PM
To: ccielab@groupstudy.com
Subject: multihomed non-transit AS configuration
I am wanting to connect our two routers (A,B both in AS 16895) to two
different ISPs (ISP-4323, ISP-16895) and had a few questions about
making them talk to each other, and to the ISPs.
They already have loopbacks and am not sure if I need ebgp-multihop or
some other commands.
Router A
interface serial 0
ip addr 192.168.1.1 255.255.255.252
description to ISP-4323
interface loopback 0
ip addr 10.0.0.1
router bgp 16895
network 216.54.167.0 mask 255.255.255.0
network 216.54.168.0 mask 255.255.255.0
network 216.54.169.0 mask 255.255.255.0
network 216.54.170.0 mask 255.255.255.0
no sync
neighbor 192.168.1.2 remote-as 4323
neighbor 192.168.1.2 update-source loopback 0
neighbor 10.0.0.11 remote-as 16895
neighbor 10.0.0.11 update-source loopback0
RouterB
interface serial 0
ip addr 172.16.1.1 255.255.255.252
description to ISP-4323
interface loopback 0
ip addr 10.0.0.11 255.255.255.255
router bgp 16895
network 216.54.167.0 mask 255.255.255.0
network 216.54.168.0 mask 255.255.255.0
network 216.54.169.0 mask 255.255.255.0
network 216.54.170.0 mask 255.255.255.0
neighbor 172.16.1.2 remote-as 3847
neighbor 172.16.1.2 update-source loopback 0
neighbor 10.0.0.1 remote-as 16895
neighbor 10.0.0.1 update-source loopback0
ISPA
ISPB
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 08:23:56 GMT-3