From: Mingzhou Nie (mnie@xxxxxxxxx)
Date: Tue Aug 27 2002 - 17:19:34 GMT-3
Angelo,
The exact problem has been discussed a week ago. It's because
172.16.220.0 is not synced on r10. As Colin pointed out, "show ip bgp
172.16.220.0 on R10" will prove that. If a route is not synced, then
it's not even been put into best path selection process.
Ming
--- Colin Barber <Colin.Barber@telewest.co.uk> wrote:
> what is the output of show ip bgp 172.16.220.0 on R10?
>
> -----Original Message-----
> From: Angelo De Guzman [mailto:ghie_pogi@yahoo.com]
> Sent: 27 August 2002 13:23
> To: 'ccielab@groupstudy.com'
> Subject: Page 376 of Internet Routing by Halabi
>
>
> Hi to All,
>
>
> R10 ------R7
> | /
> | /
> | /
> R5
>
> R10 and R7 in AS 1.
> R5 in AS 3
>
> My objective is for R10 to prefer the path to R7
> going into AS 5. I'm only allowed to change the metric
> to make this work. The link between R5 and R10 will
> only be used when R5 to R7 link fails.
>
> Here's my Config.
>
> R5
>
> router BGP 3
> network 172.16.220.0 mask 255.255.255.0
> neighbor 172.16.20.1 remote-as 1
> neighbor 172.16.20.1 route-map setmetric out
> neighbor 192.68.6.2 remote-as 1
> neighbor 192.68.6.2 route-map setmetric1 out
> no auto-summary
>
> route-map setmetric permit 10
> set metric 100
>
> route-map setmetric1 permit 10
> set metric 50
>
> These are the sh ip bgp for R7 and R10
>
> R10#sh ip bgp
> BGP table version is 3, local router ID is 192.68.11.1
> 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
> *> 172.16.220.0/24 172.16.20.2 100 0 3 i
> * i 192.68.6.1 50 100 0 3 i
> *> 192.68.11.0 0.0.0.0 0 32768 i
>
>
> R7#sh ip bgp
> BGP table version is 7, local router ID is 192.68.9.2
> 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
> * i172.16.220.0/24 172.16.20.2 100 100 0 3
> i
> *> 192.68.9.1 50 0 3
> i
> *>i192.68.11.0 192.68.6.2 0 100 0 i
>
> Why does R10 still prefers the link between R10 and
> R5. Eventhough the network 172.16.220.0/24 has a
> metric of 100.
> Thanks,
> Angelo
>
>
This archive was generated by hypermail 2.1.4 : Sat Sep 07 2002 - 19:48:39 GMT-3