From: Tony Schaffran (groupstudy@cconlinelabs.com)
Date: Sat Apr 03 2004 - 12:18:56 GMT-3
Ahmed,
Actually, the ping timed out, not because the other side was a backup
interface as well, but because the backup interface will not come up if you
just shutdown the interface. You did not mention exactly how you disabled
the frame relay interface, so I assume you just did a shutdown. With a
shutdown, the interface status should be UP/DOWN. The line will still be
UP. For the backup interface to come up, the line needs to be DOWN. You
should be able to simulate this by simply changing the LMI to something
else.
If I am incorrect in my assumption, then just disregard this email.
Cheers,
Tony Schaffran
Network Analyst
CCIE #11071
CCNP, CCNA, CCDA,
NNCDS, NNCSS, CNE, MCSE
www.cconlinelabs.com
Your #1 choice for online Cisco rack rentals.
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Ahmed Mustafa
Sent: Friday, April 02, 2004 9:51 PM
To: ccielab@groupstudy.com
Subject: Wanted to share with the Group about ISDN Backup issue
R4 and R5 are connected via Frame-Relay and backup intereface via ISDN.
Here is the interesting situation. Both routers should have complete IP
reachibility incase either of their Frame-Relay interface goes down.
I took an approach to used backup interface for both routers.
For example,
r4
int s0
backup interface bri 0
r5
int s0
backup interface bri 0
I took the Frame-Relay interface down at R4 and since ICMP traffic was the
only interesting traffic I pinged the other side, but it timed out. I
spent
little time to see why I can't ping the interface as I was able to ping it
before configuring the backup commands. I then realized ofcourse, I can't
because the other side's backup interface is down, and wouldn't come up
until
I brought it down the s0 manually as well at the other site.
The moral of the story is in the real lab always eliminate the back
interface
configuration if Lab asks youto back up both ends if either of the primary
interface goes down. The only way this could work if lab specifically
states
that both primary interfaces go down at the same time.
Any thought?
Regards,
Ahmed
This archive was generated by hypermail 2.1.4 : Mon May 03 2004 - 19:48:43 GMT-3