From: Angelo De Guzman (ghie_pogi@xxxxxxxxx)
Date: Wed Aug 28 2002 - 23:23:12 GMT-3
Hi To all,
I was able to solved this problem by putting in
no-synchronization under my router bgp configuration
(R10 and R7). Somebody from the list posted that a
route is not put into the BGP path selection process
if the route is not synchronized. My config below
works fine by just adding the no-sync.
always-compare-med won't solved this problem
because the metric of the route does not come from a
different AS. As I've read, by default BGP always
compare the MED when an update for a route comes from
the same AS. And as an addition to this as I may say,
you have to have that route synchronized before it is
put into the bgp path selection process.
Please correct me if I'm wrong...
Thanks to all,
Angelo
--- Khalid Siddiq <khalid@sys.net.pk> wrote:
> Chech the next-hop ip address 192.68.6.1 on R10
> router, it should be in routing table.
> khalid
>
> -----Original Message-----
> From: Colin Barber
> [mailto:Colin.Barber@telewest.co.uk]
> Sent: Wednesday, August 28, 2002 3:14 PM
> To: 'Graham, John'; 'ccielab@groupstudy.com'
> Subject: RE: Page 376 of Internet Routing by Halabi
>
>
> MED is being sent from R5 in AS3 to two routers (R7
> and R10) in AS1.
> Therefore the two routes being compared on R7 and
> R10 have MED values from a
> single AS.
>
> Colin
> -----Original Message-----
> From: Graham, John [mailto:john.graham@cgey.com]
> Sent: 28 August 2002 10:54
> To: 'Colin Barber'; 'Robert Miller';
> 'ccielab@groupstudy.com'
> Subject: RE: Page 376 of Internet Routing by Halabi
>
>
> Isn't he trying to prefer one route to a destination
> over another on a local
> basis ?
>
> -----Original Message-----
> From: Colin Barber
> [mailto:Colin.Barber@telewest.co.uk]
> Sent: 27 August 2002 14:32
> To: 'Robert Miller'; 'ccielab@groupstudy.com'
> Subject: RE: Page 376 of Internet Routing by Halabi
>
>
> You shouldn't need 'always-compare-med' as the route
> is being advertised by
> only one AS (AS3)
>
> Colin
> -----Original Message-----
> From: Robert Miller [mailto:rmiller@absitech.com]
> Sent: 27 August 2002 14:17
> To: ccielab@groupstudy.com
> Subject: RE: Page 376 of Internet Routing by Halabi
>
>
> Refer to the rules for comparing Med for external
> vs. internal AS's
>
> "always-compare-med"
>
> Robert
> ------------------------------------------------
> On Tue, 27 Aug 2002 05:22:36 -0700 (PDT), Angelo De
> Guzman
> <ghie_pogi@yahoo.com> wrote:
>
> > 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 - 19:48:41 GMT-3