[c-nsp] condition BGP quastion
Nikolai Abromov
nabromov at gmail.com
Fri Jan 28 03:34:11 EST 2005
Hi Bruce,
First - thanks for your reply I know about bgp condition , but I'm not
quite sure how to setup the rule and there is the problem
uplink1 uplink2
| |
[router A] - [router B]
|
[customer]
and both uplinks are marked with community strings where first
uplinks is (xxx:001) the second is (xxx:002), I tried to made when the
routes from second
uplink disappear then advertise prefix-list which is in route-map
"advertize" to uplink1
the configuration is something like this
route-map track-as1111, permit, sequence 10
Match clauses:
community (community-list filter): 150
Set clauses:
Policy routing matches: 0 packets, 0 bytes
route-map advertize, permit, sequence 10
Match clauses:
ip address prefix-lists: advertise-this
Set clauses:
Policy routing matches: 0 packets, 0 bytes
[..]
neighbor 192.168.1.1 advertise-map advertize non-exist-map track-as1111
..
so it's that possible or I do something wrong?
On Thu, 27 Jan 2005 10:41:38 -0800, Bruce Pinsky <bep at whack.org> wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Nikolay Abromov wrote:
> | Hello List,
> |
> | I have two (bgp) uplink providers which is located on different routers
> | in local segment and i'm wondering is there any method to make backup of
> | my customers with advertise-maps with this topology?
> |
> | scheme:
> |
> | (uplink) (uplink)
> | | |
> | [router A] --- [router B]
> |
> |
>
> Assuming you mean to only advertise your customer's route via router B to
> provider #2 only if the connection via router a to ISP #1 fails, then yes
> you can. That is called conditional BGP advertisement. See
>
> http://www.cisco.com/en/US/tech/tk365/technologies_q_and_a_item09186a00800949e8.shtml#fifteen
>
> and
>
> http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a0080094309.shtml
>
> for more info.
>
> Of course, the other provider must allow you to advertise the customer's
> route so verify that they have their filters set properly.
>
> - --
> =========
> bep
>
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.0 (MingW32)
>
> iD8DBQFB+TXhE1XcgMgrtyYRAt2TAKC52qXP+e41dFvrYy0dA4hKac7tuACg5Sho
> skad6gxMExohmelH3bQLDIs=
> =bWpe
> -----END PGP SIGNATURE-----
>
More information about the cisco-nsp
mailing list