From: Joseph Brunner (joe@affirmedsystems.com)
Date: Sun Nov 18 2007 - 23:05:36 ART
For the answer we head back to a live rack of routers;
I will give you some scenarios and how I solve each...
Consider R6, peering ebgp with BB1 (AS54) in my rack... (I have lowered the
timers to keepalive 3 and holdtime 9)
Router6 has no password configured
BB1 has password configured as CISCO
rack1r6#debug ip bgp
BGP debugging is on
rack1r6#clear ip bgp 54
.Nov 19 01:56:39.450: BGP: 150.1.1.254 open active, delay 23497ms
.Nov 19 01:57:02.949: BGP: 150.1.1.254 open active, local address 150.1.1.6
.Nov 19 01:57:07.949: BGP: 150.1.1.254 open failed: Connection timed out;
remote host not responding
So as you see we are dead in the mud, nothing from BB1... perhaps we should
try any password?
rack1r6(config)#router bgp 65001
rack1r6(config-router)#nei 150.1.1.254 password PASS
rack1r6#clear ip bgp 54
(ah, so we are getting somewhere)
.Nov 19 02:00:52.629: %TCP-6-BADAUTH: Invalid MD5 digest from
150.1.1.254(63259) to 150.1.1.6(179)
.Nov 19 02:00:54.629: %TCP-6-BADAUTH: Invalid MD5 digest from
150.1.1.254(63259) to 150.1.1.6(179)
.Nov 19 02:00:58.627: %TCP-6-BADAUTH: Invalid MD5 digest from
150.1.1.254(63259) to 150.1.1.6(179)
.Nov 19 02:01:06.628: %TCP-6-BADAUTH: Invalid MD5 digest from
150.1.1.254(63259) to 150.1.1.6(179)
Now at least we know BB1 is using AUTHENTICATION...
As it an MD-5 hash sent on the wire, good luck cracking it...
-Joe
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Enyi
Abajue
Sent: Sunday, November 18, 2007 8:16 PM
To: Cisco certification
Subject: Knowing when authentication is turned on for a backbone router
Hello,
Does anyone know how to determine when authentication is configured on a BB
router for a bgp session. I would like to know just in case I can't get a
peer up and somehow a password is required and it was omitted. Is there a
way to determine that authentication is required by a peer?
Thank you.
This archive was generated by hypermail 2.1.4 : Sat Dec 01 2007 - 06:37:30 ART