From: Shahid Ansari (shahid1357@gmail.com)
Date: Tue Aug 05 2008 - 09:25:17 ART
Dear Monica,
L2 network uses Spanning tree to prevent loop in the reduntant network. To
avoid it put all the vlans in spanning tree .
important thing is that L2 frame doesnot have TTL field so if loop happens
solution is to break physically(you will loose connectivity to core and
other switches ) shut down secondary core for troubleshooting and try to
trouble shoot.
chk your cpu utilization on core switch you can check process detail and if
it increases more than 20% with STP most probably loop occurs .Chk broadcast
,Multicast on giga port of core switch ,if huge broadcast,multicast catch
the port .
Enable udld/loopguard to avoide it.
L3 loops (routing Loop) occurs if routing protocol is looses its originality
(Mutual redistribution on ASBR) and split-horizon,triggered update,poison
reverse and hold down timers .
L3 has TTL field but if loop occurs even though TTL is high will not get
reachability.
Thanks
Shahid Ansari
On Tue, Aug 5, 2008 at 3:04 PM, Monica Belluci <mpls1979@gmail.com> wrote:
> Dear Gs,
>
> What is difference between L2 loop and L3 loop ? how to avoide them ?
>
> Thanks
> Monica
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
Blogs and organic groups at http://www.ccie.net
This archive was generated by hypermail 2.1.4 : Mon Sep 01 2008 - 08:15:29 ART