Matthew,
In your current configuration you have a route-map "com1" with a
sequence of 10 in which BGP will look at first as you recieve updates from
neighbor R1. Now, within that route map you have specified "match ip address
3", so in acl 3 you are PERMITTING 10.3.2.0/24 and then set acl 3 to
expanded community 100.. whatever that states..? (I dont see this in your
config for R2). Now if nothing else matches that sequence number 10 then
move on to the next sequence number which is "com1 permit 20" in which you
are saying that if the route does not match sequence 10 then everything else
learned via BGP from that neighbor should match sequence 20 "do not
advertise to other peers" in other words, all routes received carrying this
value are not advertised to other BGP peers. All in all you have configured
this so that you can and will see 10.3.2.0/24 on R2 bgp table for
advertising from what I can see.. since you have matched a value for it to
do so..
-Sal
Matthew Webster wrote:
>
> Hi all,
>
> I have a few problems with configuring route maps in
> conjunction with BGP.
>
> I have configured a community that advertises all networks
> except two but these two networks are still advertised to the
> peer after doing the clear ip bgp * command on both peers.
>
> I have read in the Cisco book that route-maps are applied to
> incoming packets, therefore I need to configure my route-map on
> R2, which is connected to R1 over a serial link (R1 has all the
> routes to advertise in the BGP AS).
>
> I'm assuming the logic in my route-map is like this: "if
> 10.3.2.0/24 is received in a BGP update, then do not allow that
> route to be entered into the BGP route table, however allow all
> other routes to be enetered into the BGP route table". Howevere
> when I do a sh ip bgp it still includes 10.3.2.0/24.
>
> Perhaps R2 will still insert the route into its own route
> tabel, but not advertise it out to the next router (R3, which
> is not connected directly to R1) - does anybody know? Here is
> the topology:
>
> R1----------R2-----------R3
>
> Here is the configuration on R2:
>
> router bgp 100
> no synchronization
> neighbor 1.1.1.1 remote-as 100
> neighbor 1.1.1.1 update-source Loopback0
> neighbor 1.1.1.1 send-community
> neighbor 1.1.1.1 route-map com1 in
> !
> ip classless
> ip route 1.1.1.1 255.255.255.255 192.168.100.1
>
> access-list 3 permit 10.3.2.0 0.0.0.255
>
> route-map com1 permit 10
> match ip address 3
> set community 100
> !
> route-map com1 permit 20
> set community no-advertise
>
> and on R1:
>
> interface Ethernet0
> ip address 10.2.2.1 255.255.255.0 secondary
> ip address 10.3.2.1 255.255.255.0 secondary
> ip address 10.4.2.1 255.255.255.0 secondary
> ip address 10.5.2.1 255.255.255.0 secondary
> ip address 10.6.2.1 255.255.255.0 secondary
> ip address 10.7.2.1 255.255.255.0 secondary
> ip address 10.8.2.1 255.255.255.0 secondary
> ip address 10.9.2.1 255.255.255.0 secondary
> ip address 10.10.2.1 255.255.255.0 secondary
> ip address 10.1.2.1 255.255.255.0
>
> router bgp 100
> network 10.1.2.0 mask 255.255.255.0
> network 10.2.2.0 mask 255.255.255.0
> network 10.3.2.0 mask 255.255.255.0
> network 10.4.2.0 mask 255.255.255.0
> network 10.5.2.0 mask 255.255.255.0
> network 10.6.2.0 mask 255.255.255.0
> network 10.7.2.0 mask 255.255.255.0
> network 10.8.2.0 mask 255.255.255.0
> network 10.9.2.0 mask 255.255.255.0
> network 10.10.2.0 mask 255.255.255.0
> neighbor 2.2.2.2 remote-as 100
> neighbor 2.2.2.2 update-source Loopback0
>
> TIA,
> Matthew.
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=74425&t=74424
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