From: damien (damien@xxxxxxxxxxx)
Date: Tue Oct 03 2000 - 15:09:51 GMT-3
it looks good to me.....the only thing is, I don't know if this is just a
mail typo.....but route-map r4 .......is missing the ....r....!!
if that is a typo......then I see know reason why this does not work...I
have tried it in the Lab and it works no problem......
This is an example:
The route map associated with the non-exist-map specifies the prefix
that the BGP speaker tracks. The route-map associated with the
advertise-map specifies the prefix that is advertised when the prefix in
the non-exist-map no longer exists.
The prefix tracked by the BGP speaker must be present in the BGP table
for the conditional advertisement not to take place. For instance, in
the example below, the router advertises 131.108.0.0/16 to its
neighbor only if 192.31.7.0/24 is not present in the BGP table.
!
router bgp 109
neighbor 160.89.2.33 remote-as 2051
neighbor 160.89.2.33 advertise-map ISP2-subblock non-exist-map
ISP2-backbone
!
route-map ISP2-subblock permit 10
match ip address 1
!
route-map ISP2-backbone permit 10
match ip address 2
!
access-list 1 permit 131.108.0.0
access-list 2 permit 192.31.7.0
Thanks
D
----- Original Message -----
From: "Dino" <air@ihug.co.nz>
To: <ccielab@groupstudy.com>
Sent: Tuesday, October 03, 2000 8:56 AM
Subject: Re: Conditional BGP Advertisements
> Hi all,
>
> I'm also having problem trying to get this conditional BGP advertisement
> to work.
>
> Here is the config of the router that is doing conditional BGP
> advertisement.
>
> router bgp 2
> no synchronization
> network 10.1.23.0 mask 255.255.255.0
> network 10.1.42.0 mask 255.255.255.0
> network 10.1.52.0 mask 255.255.255.0
> network 10.20.1.0 mask 255.255.255.0
> neighbor 10.1.23.3 remote-as 3
> neighbor 10.1.23.3 advertise-map r5 non-exist-map r4
> neighbor 10.1.42.4 remote-as 4
> neighbor 10.1.52.5 remote-as 5
> no auto-summary
> !
> access-list 4 permit 172.27.0.0
> access-list 5 permit 192.168.5.0
> route-map 4 permit 10
> match ip address 4
> !
> route-map r5 permit 10
> match ip address 5
>
> The problem I have is that my router in AS3 is still seeing 192.168.5.0
> eventhough 172.27.0.0 is still present in the above router BGP table.
> Are there any tricks in getting this to work?
>
> Thanks,
>
> Dino
>
>
> Bell, Mark (Houston) wrote:
> >
> > I have attempted to configure a conditional advertisement in my network
> > using the following config:
> >
> > router bgp 3
> > no synchronization
> > neighbor 10.10.1.3 remote-as 2
> > neighbor 10.10.1.3 advertise-map BACKUP non-exist-map BACKUP2
> > neighbor 10.10.1.5 remote-as 3
> > neighbor 10.10.1.5 route-reflector-client
> > neighbor 10.20.1.2 remote-as 3
> > neighbor 10.20.1.2 route-reflector-client
> > !
> > ip classless
> > no ip http server
> > ip as-path access-list 1 permit _\(65005\)$
> > !
> > access-list 1 permit 6.0.0.0
> > access-list 2 permit 11.1.0.0
> > route-map BACKUP permit 10
> > match ip address 1
> > !
> > route-map ASPATH permit 10
> > match as-path 1
> > set local-preference 500
> > !
> > route-map BACKUP2 permit 10
> > match ip address 2
> >
> > When I go to the router 10.10.1.5 that advertises 11.1.0.0/16 and shut
down
> > it's link to this router, 11.1.0.0/16 disappears from the BGP table as
> > expected. If I understand conditional advertisements correctly, the
router
> > should begin advertising 6.0.0.0/8 to 10.10.1.3 because 11.1.0.0/16 is
gone.
> > The problem is, 6.0.0.0/8 never shows up anywhere.
> >
> > Does the backup route have to be present in the BGP table prior to the
> > monitored route disappearing or will it be injected into the BGP table
only
> > when necessary? Are there any restrictions as to whether the monitored
or
> > backup route must be learned via iBGP or eBGP?
> >
> > -----Original Message-----
> > From: Stylen [mailto:globalfx@netropolis.net]
> > Sent: Friday, September 29, 2000 21:26
> > To: ccielab@groupstudy.com
> > Subject: Re: Conditional BGP Advertisements
> >
> > Yes, BGP will look for the route in its routing table, if it goes away,
then
> > the routes in the advertise list will be advertised via eBGP. this is
used
> > for backing up a link, i.e. if you have two routers connected to to a
> > external network. You might only want one of them advertising a specific
> > route, perhaps because of location, but if the link between that router
and
> > the external network goes down, then the second router will begin
> > advertising the route for redundancy. if you have the second router
watch
> > for the link between the first router and the external network in its
> > routing table, when the route goes dissappears, then it knows to
advertise
> > the route designated by advertise-map.
> >
> > Internet
> > | |
> > | |204.0.0.4/30
> > R1------R2
> > |
> > |
> > 204.2.3.0/24
> > the 204.0.0.5 route will be in R1's routing table, via a IGP. when the
link
> > between R2 and the internet goes down, then the 204.0.0.5 route will
> > dissappear from the routing table in R1 then R1 will advertise the route
to
> > 204.2.3.0/24 to the internet. When the 204.0.0.4/30 route comes back up,
R1
> > will stop advertising 204.2.3.0/24, and R2 will take over.
> >
> > Richard Foltz, CCNP, CCNP-Voice, CCDP, MCSE+I, Network+, A+
> > Technical Solutions Consultant
> > Sprint ENS
> >
> > -----Original Message-----
> > From: abdul_rahim@ccsi.canon.com <abdul_rahim@ccsi.canon.com>
> > To: ccielab@groupstudy.com <ccielab@groupstudy.com>
> > Date: Friday, September 29, 2000 7:58 PM
> > Subject: Conditional BGP Advertisements
> >
> > >The following statement as described on cisco in BGP routing process
> > >neighbor a.b.c.d advertise-map <route-map 1> no-exist-map <route-map 2>
> > >
> > >
> > >Advertises the routes specified in route-map1 when it finds that the
routes
> > >specified in route-map 2 does not exists any more in the BGP table
> > >And they call it as Conditional Advertisement
> > >
> > >My question is that the routes in route-map1 ,do they have to be
present in
> > >the BGP table,
> > >I am not getting the point at all
> > >
> > >Can some body explain it to all of the group in a bit detail or
redirect to
> > >a certain URL ,I do have the URL on cisco sit
> > >http://cisco.com/warp/public/459/34.html
> > >
> > >Any feedbacks would be highly appreciated
> > >Thanks
> > >Abdul
> > >
> > >
> > >
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 08:25:23 GMT-3