11-01-2005 07:55 PM - edited 03-03-2019 10:52 AM
I have 4 routers ruuning in BGP AS1 and adopting EIGRP 100 as IGP. The connection looks like the following:
R0(interface e0)----(interface e0)R5(interface s1)-----(interface s1)R6(interface s0)----(interface S1)R4.
And the follwoing is the list of the configuration:
R0#
interface Ethernet0
ip address 172.16.1.1 255.255.255.0
no ip route-cache
router bgp 1
no synchronization
bgp log-neighbor-changes
neighbor 172.15.1.4 remote-as 1
neighbor 172.15.1.6 remote-as 1
neighbor 172.16.1.2 remote-as 1
auto-summary
R5#sh run
interface Ethernet0
ip address 172.16.1.2 255.255.255.0
!
interface Serial0
ip address 10.10.10.5 255.255.255.252
no fair-queue
!
interface Serial1
ip address 32.1.1.5 255.255.255.252
!
router eigrp 100
network 32.0.0.0
network 172.16.0.0
no auto-summary
!
router bgp 1
no synchronization
bgp log-neighbor-changes
redistribute eigrp 100 metric 50 route-map localOnly
neighbor 32.1.1.6 remote-as 1
neighbor 172.15.1.6 remote-as 1
neighbor 172.16.1.1 remote-as 1
no auto-summary
!
ip classless
ip http server
!
access-list 1 permit 32.1.1.0
route-map localOnly permit 10
match ip address 1
R6#sh run
interface Serial0
ip address 172.15.1.4 255.255.255.0
no ip route-cache
no ip mroute-cache
no fair-queue
clockrate 2000000
!
interface Serial1
ip address 32.1.1.6 255.255.255.252
no ip route-cache
no ip mroute-cache
clockrate 2000000
!
router eigrp 100
network 32.0.0.0
network 172.15.0.0
no auto-summary
!
router bgp 1
no synchronization
bgp log-neighbor-changes
redistribute eigrp 100 metric 50 route-map localOnly
neighbor 32.1.1.5 remote-as 1
neighbor 172.15.1.6 remote-as 1
neighbor 172.16.1.1 remote-as 1
no auto-summary
access-list 1 permit 32.1.1.0
route-map localOnly permit 10
match ip address 1
interface Serial1
ip address 172.15.1.6 255.255.255.0
no ip route-cache
!
interface BRI0
no ip address
no ip route-cache
shutdown
!
router eigrp 100
network 172.15.0.0
no auto-summary
!
router bgp 1
no synchronization
bgp log-neighbor-changes
neighbor 172.15.1.4 remote-as 1
neighbor 172.16.1.1 remote-as 1
neighbor 172.16.1.2 remote-as 1
no auto-summary
the reason I want to config the route-map on the R6 and R5 is I only want to R6 and R5 announce the network 32.1.1.0/24. But looks like R6 did not advertise 32.1.1.0 towards R4:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
R6#sh ip bgp nei 172.15.1.6 ad
~~~~~~~~~~nothing showed~~~~~~~~~~~~~~~~
R6#
When I added one more route-map:
route-map localOnly permit 100
All the network been advertised out:
R6#sh ip bgp nei 172.15.1.6 ad
BGP table version is 68, local router ID is 6.6.6.6
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 32.1.1.4/30 0.0.0.0 0 32768 ?
*> 172.15.1.0/24 0.0.0.0 0 32768 ?
*> 172.16.1.0/24 32.1.1.5 50 32768 ?
*> 172.17.1.4/30 32.1.1.5 50 32768 ?
How do i do to only allow the network 32.1.1.0/24 to be advertised ?
11-01-2005 08:02 PM
Sorry, for that, I mis-configured access-list. It should be "access-list 1 permit 32.1.1.4 0.0.0.3"
11-02-2005 11:26 AM
Dear,
to advertise only the above network you could try the following configurations:
router bgp 1
no synchronization
bgp log-neighbor-changes
redistribute eigrp 100 metric 50 route-map out-routes
route-map out-routes permit 10
match ip address prefix-list out-routes
ip prefix-list out-routes seq 1 permit 32.1.1.0/24
and make sure that the subnet 32.1.1.0/24 is added in your routing tabel with the same prefix
Another woraorund you can appliy you BGP filtering in the incoming routes on R5 by the following
R5(config-router)#neighbor 32.1.1.6 remote-as 1
R5(config-router)#neighbor 32.1.1.6 prefix-list incoming in
R5(config)#ip prefix-list incoming seq 1 permit 32.1.1.0/24
Best Regards,
Mounir Mohamed
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