From: damien (damien@xxxxxxxxxxx)
Date: Thu Oct 05 2000 - 07:34:13 GMT-3
Changes below:
access-list 20 permit 172.16.3.0
access-list 30 permit 172.16.2.0
The following reads like this, "neighbor 195.211.10.1 advertise-map
advertise non-exist-map noexist" when sending updates to neighbor 19211.10.1
, check route-map advertise and noexist.............if the route specified
in the noexist route-map is not in the bgp table....then adverties what
routes are specified in advertise route-map............and vice
verse...........
----- Original Message -----
From: <abdul_rahim@ccsi.canon.com>
To: "damien" <damien@clara.co.uk>
Cc: "Dino" <air@ihug.co.nz>; <ccielab@groupstudy.com>
Sent: Wednesday, October 04, 2000 11:23 PM
Subject: Re: Conditional BGP Advertisements
>
> Hi all
> I have two Routers
> RE------RG
>
> RTE:
> interface Loopback1
> ip address 172.16.2.1 255.255.255.0
> !
> interface Loopback2
> ip address 172.16.3.1 255.255.255.0
>
> router bgp 400
> no synchronization
> network 172.16.2.0 mask 255.255.255.0
> network 172.16.3.0 mask 255.255.255.0
> neighbor 195.211.10.1 remote-as 500
> neighbor 195.211.10.1 prefix-list abc in
> neighbor 195.211.10.1 advertise-map advertise non-exist-map noexist
> no auto-summary
>
> access-list 20 permit 172.16.10.0
> access-list 30 permit 172.16.3.0
> route-map advertise permit 10
> match ip address 20
> !
> route-map noexist permit 10
> match ip address 30
>
> RTG:
> BGP Table
>
> *> 172.16.2.0/24 195.211.10.2 0 0 400 i
> *> 172.16.3.0/24 195.211.10.2 0 0 400 i
> RTG#
>
> I want to advertise to RTG 172.16.3.0/24 only if the network 172.16.2.0/24
misses in the BGP table
> But In normal Circumstances I see both the route available to RTG
> Why isn't the neighbor 195.211.10.1 advertise-map advertise non-exist-map
noexist statement working above
> I think I am missing some thing,If I already advertised the network (
172.16.3.0/24 ) via BGP then It will definitely get advertised to all the
> neighbours would it check for the route-map statement to get advertised
conditionally
> I thibk some of you can help me in this scenario
> Thanks
> Abdul
>
>
> Plz lok into my configs to find whats the thing I am missing for
> conditional advertisement in BGP
>
>
>
>
>
> "damien" <damien@clara.co.uk>@groupstudy.com on 10/03/2000 11:09:51 AM
>
> Please respond to "damien" <damien@clara.co.uk>
>
> Sent by: nobody@groupstudy.com
>
>
> To: "Dino" <air@ihug.co.nz>
> <ccielab@groupstudy.com>
> cc:
> Subject: Re: Conditional BGP Advertisements
>
>
> 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 - 08:25:24 GMT-3