[c-nsp] BGP conditional advertisemet - NON-EXIST route map'saccess-list problem

[Burak Dikici]

 I have made a change on the lab with the commands which are written below ,
but ISP-2 still getting my announcment. No success...


ip as-path access-list 1 permit ^200  (ISP-1 AS number)

ip prefix-list AS200-track seq 5 permit 192.168.200.0/24 (subnet
between multihoming router and ISP-1 router)

route-map NON-EXIST permit 10
 match ip address prefix-list AS200-track
 match as-path 1

router bgp 10
 neighbor 192.168.100.1 advertise-map ADVERTISE non-exist-map NON-EXIST








On Sun, Mar 15, 2009 at 11:03 PM, <RPhookun at lecg.com> wrote:

>
> I agree with Ivan in that the tracked prefix  in the Non-Exist-Map should
> be the ISP-1 infrastructure address because in its absence you wouldn't be
> receiving any other routes from ISP-1
> However, the match of the tracked prefix is from the BGP table *not* the IP
> routing table and "match-as-path" can be very relevant in some topologies
> and its absence in the Non-Exist-Map can cause the conditional advertisement
> feature to break.
>
> Cisco has an excellent example - "Configuring and Verifying the Conditional
> Advertisement Feature"
>
> ./Randy
>
>
>
>
>
>   *"Ivan Pepelnjak" <ip at ioshints.info>*
> Sent by: cisco-nsp-bounces at puck.nether.net
>
> 03/15/2009 12:48 PM
>    To
>  "'Burak Dikici'" <bdikici at gmail.com>
>  cc
>   cisco-nsp at puck.nether.net  Subject
> Re: [c-nsp] BGP conditional advertisemet - NON-EXIST route
>  map'saccess-list problem
>
>
>
>
>
>  That's the problem everyone has with the NON-EXIST-MAP :) Usually the IP
> prefix used to address the ISP-1 infrastructure is the best bet.
>
> The "match as-path" statement in the NON-EXIST-MAP is irrelevant (unless
> I'm
> totally wrong about the match being made with the routes in the IP routing
> table :).
>
> Ivan
>
>
>  _____
>
> From: Burak Dikici [mailto:bdikici at gmail.com]
> Sent: Sunday, March 15, 2009 8:19 PM
> To: Ivan Pepelnjak
> Cc: Mateusz Blaszczyk; cisco-nsp at puck.nether.net
> Subject: Re: [c-nsp] BGP conditional advertisemet - NON-EXIST route
> map'saccess-list problem
>
>
> Hi Ivan ,
>
> Ok than , what should i use for  NON-EXIST route-map's access-list ? Which
> prefix should i trust from ISP-1 (Primary ISP) ?
> Is it necessary to use  "match ip address" and "match as-path" statements
> together in the  NON-EXIST route-map ?
>
>
> On Sun, Mar 15, 2009 at 8:46 PM, Ivan Pepelnjak <ip at ioshints.info> wrote:
>
>
> You can't use "permit any" because it would match any route in the IP
> routing table (including the connected interfaces). The access list used in
> NON-EXIST-MAP is used on the IP routing table, not on the BGP table (that's
> why the AS path doesn't work either).
>
> Ivan
>
>
> > -----Original Message-----
> > From: Burak Dikici [mailto:bdikici at gmail.com]
> > Sent: Sunday, March 15, 2009 7:16 PM
> > To: Mateusz Blaszczyk
> > Cc: cisco-nsp at puck.nether.net
>
> > Subject: Re: [c-nsp] BGP conditional advertisemet - NON-EXIST
> > route map'saccess-list problem
> >
>
> > Hi Mateusz ,
> >
> > For better understanding , i have attached the topology
> > screenshot and the router's configuration files. (By the way
> > , this is a lab config.)
> >
> > In the attached Router's configuration ,
> >
> > access-list 65 permit 172.16.1.0 0.0.0.255
> >
> > command is used and with this command bgp conditional
> > advertisement is working fine.
> >
> > But when i use ,
> >
> > access-list 65 permit any
> >
> > command , the conditional advertisement doesn't work.
>
>
>
>
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
>
>