From: Brian Lodwick (xpranax@xxxxxxxxxxx)
Date: Thu Mar 21 2002 - 20:00:29 GMT-3
Since 3 and 2 are the decision makers here and 2 and 4 are in the same AS I
would suggest using MED's to influence 3's decision on how to get to network
172.16.1.0/24, and I would simply add a prefix-list to 3 so that 2 only
hears about the route to network 200.128.1.0/24 from 4.
r1
router bgp 5
neighbor r2 remote-as 2001
neighbor r4 remote-as 2001
network 172.16.1.0 mask 255.255.255.0
r2
router bgp 2001
neighbor r1 remote-as 5
neighbor r3 remote-as 2010 route-map MED out
neighbor r4 remote-as 2001
!
route-map MED permit 10
set metric 50
route-map MED permit 20
r3
router bgp 2010
neighbor r2 remote-as 2001 prefix-list NoR2 out
neighbor r4 remote-as 2001
network 200.128.1.0 mask 255.255.255.0
!
ip prefix-list NoR2 deny 200.128.1.0/24 le 32
ip prefix-list NoR2 permit 0.0.0.0/0 le 32
r4
router bgp 2001
neighbor r2 remote-as 2001
neighbor r3 remote-as 2010 route-map MED out
!
route-map MED permit 10
set metric 10
route-map MED permit 20
>>>Brian
>From: Sam.MicroGate@usa.telekom.de
>Reply-To: Sam.MicroGate@usa.telekom.de
>To: CCIELAB@groupstudy.com
>Subject: A BGP question
>Date: Thu, 21 Mar 2002 16:17:21 -0500
>
> > Hello everyone,
> >
> > I have a BGP question that may be simple for a lot of you out there. I
> > have four corner routers as shown below. Router 1 is in AS5 and
> > advertising network 172.16.1.0/24. Router 3 is in AS2010 and advertising
> > network 200.128.1.0/24. Routers 2 and 4 are in AS 2001. Look at the
>figure
> > for the peering. Now the question is how can I control the route path so
> > that BGP would prefer 1 to 2 to 4 to 3 instead of 1 to 2 to 3. And also
>to
> > go from 3 to 4 to 2 to 1 instead of the shorter path 3 to 4 to 1. Thanks
>a
> > million.
> >
> >
> > 1 + 3
> > + + +
> > + + +
> > 2+++++ 4
> >
> >
> > Elsayed
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:57:16 GMT-3