From: Brian (briane@surewest.net)
Date: Wed May 10 2006 - 23:09:56 ART
That is what I originally thought. However, after reading the following
doc I do not believe that is the case.
"The reason why R2 only shows one path for 10.4.0.0/16 is because R3
withdraws (sends an update with unreachable metric) the update for
10.4.0.0/16 once it notices that R3 uses R2 to access 10.4.0.0/16 (after
running BGP bestpath on all available paths):"
http://www.cisco.com/warp/public/459/37.html
Thanks
Brian
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
ZeroFlash
Sent: Wednesday, May 10, 2006 6:53 AM
To: 'Brian'; ccielab@groupstudy.com
Subject: RE: BGP MED Question
Brian --
Not having that LAB book, if your BGP are setup properly then you should
see
both routes in the bgp table. Changing the MED should only affect the
out-bound traffic destination not the BGP table. You should see an
output
similar to R3's if BGP is setup properly.
Thanks
ZeroFlash
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Brian
Sent: Wednesday, May 10, 2006 6:50 AM
To: ccielab@groupstudy.com
Subject: BGP MED Question
I am working on task IEWB Lab 1 Task 4.3 and have a question. There is
a prefix that is originated in AS 200. There are 2 EBGP peering
sessions with AS 100. The goal is to have traffic from AS 100 destined
to AS 200 to prefer a specific path (i.e. where we are advertising the
lower MED). I am questioning what I should see when I issue sh ip bgp.
In the table for R3 I see both paths and both MED values. However in
all other routers in AS 100 I only see 1 path with the MED???
SW2 (AS200) ---> R5 (AS100) -- Med Set to 100 for specific prefix
(150.1.11.0)
R2 (AS200) ---> R3 (AS100) - Med Set to 200 for specific prefix
(150.1.11.0)
The output is similar to R5 in other routers in AS100. Any help would
be greatly appreciated.
R3#sh ip bgp
BGP table version is 33, local router ID is 150.1.3.3
Status codes: s suppressed, d damped, h history, * valid, > best, i -
internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*>i28.119.16.0/24 54.1.1.254 0 200 0 54 i
* 204.12.1.254 0 0 54 i
* 204.12.1.254 0 0 54 i
* 204.12.1.254 0 0 54 i
* i112.0.0.0 54.1.1.254 0 100 0 54 50 60 i
*> 204.12.1.254 0 54 50 60 i
* i113.0.0.0 54.1.1.254 0 100 0 54 50 60 i
*> 204.12.1.254 0 54 50 60 i
*>i114.0.0.0 54.1.1.254 0 200 0 54 i
* 204.12.1.254 0 54 i
*>i115.0.0.0 54.1.1.254 0 200 0 54 i
* 204.12.1.254 0 54 i
*>i116.0.0.0 54.1.1.254 0 200 0 54 i
* 204.12.1.254 0 54 i
*>i117.0.0.0 54.1.1.254 0 200 0 54 i
* 204.12.1.254 0 54 i
*>i118.0.0.0 54.1.1.254 0 200 0 54 i
Network Next Hop Metric LocPrf Weight Path
* 204.12.1.254 0 54 i
*>i119.0.0.0 54.1.1.254 0 200 0 54 i
* 204.12.1.254 0 54 i
*>i150.1.11.0/24 183.1.0.5 100 100 0 200 i
* 183.1.123.1 200 0 200 i
*> 205.90.31.0 183.1.123.1 0 200 254 ?
*> 220.20.3.0 183.1.123.1 0 200 254 ?
*> 222.22.2.0 183.1.123.1 0 200 254 ?
R5#sh ip bgp
BGP table version is 16, local router ID is 150.1.5.5
Status codes: s suppressed, d damped, h history, * valid, > best, i -
internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*>i28.119.16.0/24 54.1.1.254 0 200 0 54 i
*>i28.119.17.0/24 54.1.1.254 0 200 0 54 i
* i112.0.0.0 204.12.1.254 0 100 0 54 50 60 i
*>i 54.1.1.254 0 100 0 54 50 60 i
* i113.0.0.0 204.12.1.254 0 100 0 54 50 60 i
*>i 54.1.1.254 0 100 0 54 50 60 i
*>i114.0.0.0 54.1.1.254 0 200 0 54 i
*>i115.0.0.0 54.1.1.254 0 200 0 54 i
*>i116.0.0.0 54.1.1.254 0 200 0 54 i
*>i117.0.0.0 54.1.1.254 0 200 0 54 i
*>i118.0.0.0 54.1.1.254 0 200 0 54 i
*>i119.0.0.0 54.1.1.254 0 200 0 54 i
*> 150.1.11.0/24 183.1.58.8 100 0 200 i
* 205.90.31.0 183.1.58.8 100 0 200 254 ?
*>i 183.1.123.1 0 100 0 200 254 ?
* 220.20.3.0 183.1.58.8 100 0 200 254 ?
*>i 183.1.123.1 0 100 0 200 254 ?
This archive was generated by hypermail 2.1.4 : Thu Jun 01 2006 - 06:33:21 ART