From: Brian Dennis (bdennis@internetworkexpert.com)
Date: Sat Apr 09 2005 - 14:23:51 GMT-3
Tim,
You need to step back and get a working configuration first.
The configuration you have doesn't work. Also once you figure out what
commands are missing, your router R-A will no allow you to enter the
commands to do what you are trying to do ;-) Play around with it and
then think about why the router will not allow this and you'll have
figured it out.
You should have been able to tell by looking at the "show span"
that the routers do not see each other which would have indicated to you
that you do not have a working configuration.
Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security
bdennis@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987
Direct: 775-745-6404 (Outside the US and Canada)
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
ccie2be
Sent: Saturday, April 09, 2005 9:18 AM
To: Group Study
Subject: multi parallel pvc's and bridging
Hi guys,
Look at this scenario. There are 2 pvc's going between R-A and R-B. In
this
example, they just happen to be ATM, but could just as well been f/r
pvc's.
R-A's config:
interface ATM3/0
bandwidth 1544
no ip address
no atm ilmi-keepalive
pvc 100/100
!
pvc 200/200
!
bridge-group 1
R-B's config:
interface ATM3/0.1 multipoint
bandwidth 1544
pvc 100/100
!
bridge-group 1
!
interface ATM3/0.2 multipoint
bandwidth 1544
pvc 200/200
!
bridge-group 1
I've got a couple questions about this config. Maybe someone can help me
understand this better.
First, let me confirm that although the config's for R-A and R-B are
done a
little differently, functionally they're equivalent, correct?
(If that's not true, then my real questions might not make any sense.)
OK, here's what I need to understand.
Is the above config for R-A and R-B functionally equivalent to having an
etherchannel between R-A and R-B except instead of 2 physical links,
there
are 2 logical links?
I want to make sure because otherwise there would be spanning tree
issues
and one of the pvc's will be blocked.
If these 2 pvc's are being treated like an etherchannel, why is that?
From looking at these config's, I would have thought that the routers
would
treat each pvc like a physical link and then used STP to block one of
the
pvc's, but that doesn't seem to be happening. (I did a show span and
all
pvc's were forwarding.)
If someone can explain this, I'd be very grateful.
TIA, Tim
This archive was generated by hypermail 2.1.4 : Tue May 03 2005 - 07:54:55 GMT-3