From: Nauman Khan (mustafa@247emails.com)
Date: Mon Jan 26 2004 - 00:33:09 GMT-3
Hi David,
>From your config, it looks like you have 5 following networks advertised in bgp:
network 191.10.1.0 mask 255.255.255.0
network 191.10.2.0 mask 255.255.255.0
network 191.10.3.0 mask 255.255.255.0
network 191.10.4.0 mask 255.255.255.0
network 191.10.5.0 mask 255.255.255.0
If you want to create a aggregate of the first 3 , which would be /22
i.e 191.10.1.0 255.255.252.0 as you have correctly figured out.
Next, if you want only the aggregate to be "advertised" and not the more specific routes, you will use
aggregate-address 191.10.1.0 255.255.252.0 summary-only
With this command,on R2 I would expect to see one aggregate i.e
191.10.0.0 255.255.252.0
and
191.10.4.0 255.255.255.0
191.10.5.0 255.255.255.0
Your configuration looks ok to me for this part.
The only reason that I can think of that you are not seeing the aggregate/summary on R2 is b/c your route-map is missing seq 20 statement permitting all others that does not match access-list 4.
So try adding the following to your config:
route-map setcomlocal permit 20
followed by
clear ip bgp * soft
Let me know how it goes.
Thanks,
Nauman
--- David Deng <glend_99@yahoo.com> wrote:
Hi group,
I have a question on why the Aggresgate address will
suppress the address being aggregated when
summary-only key word is used, I am expecting a
summary route
191.10.0.0/22 for 191.10.1-3.0 nets.
Any remedy ?
As soon as the aggregate command is issuedm the routes
are withdrawn.
r1 has 5 loopbacks from 191.10.1.1/24-191.10.5.1/24.
lo0: 136.10.1.1 Lo0:136.10.2.2
r1 ----------------------------r2
.1 136.10.12.x .2
---------------------------------------------
r1 config:
router bgp 100
no synchronization
bgp router-id 136.10.1.1
no bgp fast-external-fallover
bgp log-neighbor-changes
bgp scan-time 15
network 191.10.1.0 mask 255.255.255.0
network 191.10.2.0 mask 255.255.255.0
network 191.10.3.0 mask 255.255.255.0
network 191.10.4.0 mask 255.255.255.0
network 191.10.5.0 mask 255.255.255.0
aggregate-address 191.10.0.0 255.255.252.0
summary-only
neighbor 136.10.2.2 remote-as 200
neighbor 136.10.2.2 ebgp-multihop 255
neighbor 136.10.2.2 update-source Loopback0
neighbor 136.10.2.2 send-community
neighbor 136.10.2.2 route-map setcomlocal out
r1-3620#sh route-map
route-map setcomlocal, permit, sequence 10
Match clauses:
ip address (access-lists): 4
Set clauses:
community local-AS
r1-3620#sh access-lists 4
Standard IP access list 4
10 permit 191.10.1.0, wildcard bits 0.0.0.255 (22
matches)
20 permit 191.10.2.0, wildcard bits 0.0.0.255 (22
matches)
30 permit 191.10.3.0, wildcard bits 0.0.0.255 (22
matches)
40 permit 191.10.4.0, wildcard bits 0.0.0.255 (18
matches)
50 permit 191.10.5.0, wildcard bits 0.0.0.255 (18
matches)
r1-3620#
------------------------------------------------
debug ip bgp neig 136.10.1.1 update
2-2611xm#
3w2d: BGP(0): 136.10.1.1 rcv UPDATE about
191.10.1.0/24 -- withdrawn
3w2d: BGP(0): 136.10.1.1 rcv UPDATE about
191.10.2.0/24 -- withdrawn
3w2d: BGP(0): 136.10.1.1 rcv UPDATE about
191.10.3.0/24 -- withdrawn
3w2d: BGP(0): 136.10.1.1 computing updates, afi 0,
neighbor version 69, table ve
rsion 72, starting at 0.0.0.0
3w2d: BGP(0): 136.10.1.1 update run completed, afi 0,
ran for 0ms, neighbor vers
ion 69, start version 72, throttled to 72
-------------------------------------------------
r2 config
r2-2611xm#sh run | beg bgp
router bgp 65251
no synchronization
bgp router-id 136.10.2.2
bgp log-neighbor-changes
bgp confederation identifier 200
neighbor 136.10.1.1 remote-as 100
neighbor 136.10.1.1 ebgp-multihop 255
neighbor 136.10.1.1 update-source Loopback0
no auto-summary
!
------------------------------------
Missing the aggregated routes.
r2-2611xm#sh ip bgp | in 191
*> 191.10.4.0/24 136.10.1.1 0 0 100 i
*> 191.10.5.0/24 136.10.1.1 0 0 100 i
David
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This archive was generated by hypermail 2.1.4 : Mon Feb 02 2004 - 09:07:50 GMT-3