RE: BGP Missing routes

From: Rik Guyler (Rik@Guyler.net)
Date: Sat Feb 22 2003 - 20:52:01 GMT-3


Svy, have you tried to turn synchronization off? One of the rules when
running IBGP is that a BGP speaker will not forward a BGP route it has
learned via IBGP until the IGP in place has learned of this route first. In
other words, R3 will not forward the route for R7 to R9 and vice-versa in
this case. Synchronization, usually on be default, will force this. To
disable it, type "no synch" under the router bgp config. The alternative is
to make sure your IGP has all of the necessary routes.

If this is not applicable, please post more info.

Rik

-----Original Message-----
From: Syv Ritch [mailto:syv@911networks.com]
Sent: Saturday, February 22, 2003 2:04 PM
To: ccielab@groupstudy.com
Subject: BGP Missing routes

Hi,

I am missing some routes in BGP [sho ip bgp].

The network is:

R9 [65109] <--> R3 [65109] <--> R7 [65109]
^ ^ ^
| | |
v v v
R5 [65110] <--> R2 [65110] <--> R6 [65110]

R9 has 2 loopbacks: 10.108.99.99/24 and 10.108.199.199/24
R3 has 2 loopbacks: 10.108.33.33/24 and 10.108.133.133/24
and so on..

All the routers peers through 99.99, 33.33 and so on..
Here is the config for R3

router bgp 65109
 bgp router-id 33.33.33.33
 bgp cluster-id 174884229
 bgp log-neighbor-changes
 network 10.108.133.0 mask 255.255.255.0
 neighbor ibgp peer-group
 neighbor ibgp update-source Loopback0
 neighbor ebgp peer-group
 neighbor ebgp ebgp-multihop 2
 neighbor ebgp update-source Loopback0
 neighbor 10.108.22.22 remote-as 65110
 neighbor 10.108.22.22 peer-group ebgp
 neighbor 10.108.77.77 remote-as 65109
 neighbor 10.108.77.77 peer-group ibgp
 neighbor 10.108.99.99 remote-as 65109
 neighbor 10.108.99.99 peer-group ibgp
!
All the other ones are similar

----------------------------------------
When doing a show ip bgp on R9, I am missing the network from R7

BGP table version is 3, local router ID is 99.99.99.99
Status codes: s suppressed, d damped, h history, * valid, > best, i -
internal Origin codes: i - IGP, e - EGP, ? - incomplete

   Network Next Hop Metric LocPrf Weight Path
* i10.108.122.0/24 10.108.22.22 0 100 0 65110 i
* i10.108.133.0/24 10.108.33.33 0 100 0 i
*> 10.108.155.0/24 10.108.55.55 0 0 65110 i
* i 10.108.22.22 100 0 65110 i
* i10.108.166.0/24 10.108.22.22 100 0 65110 i
*> 10.108.199.0/24 0.0.0.0 0 32768 i
TS-2512#7

----------------------------------------
When doing a show ip bgp on R7, I am missing the network from R9

BGP table version is 3, local router ID is 77.77.77.77
Status codes: s suppressed, d damped, h history, * valid, > best, i -
internal Origin codes: i - IGP, e - EGP, ? - incomplete

   Network Next Hop Metric LocPrf Weight Path
* i10.108.122.0/24 10.108.22.22 0 100 0 65110 i
* i10.108.133.0/24 10.108.33.33 0 100 0 i
* i10.108.155.0/24 10.108.22.22 100 0 65110 i
* i10.108.166.0/24 10.108.22.22 100 0 65110 i
*> 10.108.66.66 0 0 65110 i
*> 10.108.177.0/24 0.0.0.0 0 32768 i

----------------------------------------
When doing a show ip bgp on R3, I get all the routes that I am expecting

BGP table version is 5, local router ID is 33.33.33.33
Status codes: s suppressed, d damped, h history, * valid, > best, i -
internal Origin codes: i - IGP, e - EGP, ? - incomplete

   Network Next Hop Metric LocPrf Weight Path
*> 10.108.122.0/24 10.108.22.22 0 0 65110 i
*> 10.108.133.0/24 0.0.0.0 0 32768 i
* i10.108.155.0/24 10.108.55.55 0 100 0 65110 i
*> 10.108.22.22 0 65110 i
*> 10.108.166.0/24 10.108.22.22 0 65110 i
* i 10.108.66.66 0 100 0 65110 i
* i10.108.177.0/24 10.108.77.77 0 100 0 i
* i10.108.199.0/24 10.108.99.99 0 100 0 i

-- 
Thanks
syv@911networks.com


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