From: ccie2be (ccie2be@nyc.rr.com)
Date: Wed May 18 2005 - 16:39:45 GMT-3
Hi guys,
Yesterday I spent hours and was going nuts trying to figure out why I was
having reachability problems in the practice lab I was doing.
I was working on the IE Vol 2, lab 1 on IE rental racks.
Briefly, pings from certain points to various points were failing. To track
down the problem, I started enabling debug ip packet 100 where acl 100
captured all icmp's.
Then, I remembered that for this to work, I had to disable fast switching.
Then, as I disabled ip route-cache on various interfaces, my pings started
working.
I localized the problem to R4 which is running this IOS:
R4#sh ver
Cisco Internetwork Operating System Software
IOS (tm) C2600 Software (C2600-J1S3-M), Version 12.2(15)T10, RELEASE
SOFTWARE (
fc2)
I also disabled ip cef on various routers.
So, I have a couple questions for the GS think tank about this experience.
1. Is what happened to me because of a bug in IOS perhaps related to the
fast switching cache not being properly flushed out or refreshed?
2. In the lab, do people think it's a good idea to disable route-caching
unless explicitly forbidden? Why yes or no?
3. I always add the command, ip cef, to every router just so I don't have
to remember what features require this enabled. What do people think of
this?
4. If I'm having reachability problems in the lab and I'm highly confident
my config's are correct, I typically resort to rebooting the routers to see
if that fixes the problem and often it does. Of course, I'm reluctant to
reboot the rtr's because it takes so long. Given the above experience, does
the GS community think it wise to first disable route-cache and/or cef
before resorting to rebooting rtr's?
Thanks very much, Tim
This archive was generated by hypermail 2.1.4 : Fri Jun 03 2005 - 10:11:58 GMT-3