Redistribute only routes learned from specific BGP neighbor into OSPF (Nexus)

[Eric Brander]

I want all BGP learned routes from a specific neighbor to be redistributed into OSPF. I do not want to pick the specific routes, I trust this neighbor, so I want all of what it advertises. Can a route-map specify all routes learned from a specific neighbor? I do not want any other BGP learned routes redistributed into OSPF.

TIA,

Eric

[Akash Agrawal · Accepted solution]

Hi,

I have not tried it but you can check if we can match community through route-map while redistributing BGP routes into OSPF. If it works you can set particular community on all routes, received from the trusted neighbor.

Regards,

Akash

[siva vadakandara]

Hello There

i was also looking for suggestions on the similar concept. I was trying to choose prefixes from only one neighbor and redist them to EIGRP.

I could successfully simulate that and it is just working as i need.

note:  Naming convention used here according to my convenience. 

Config:

ISP Router:

--------------

Building configuration...

Current configuration : 1725 bytes
!
upgrade fpd auto
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname ISP
!
boot-start-marker
boot-end-marker
!
logging message-counter syslog
!
no aaa new-model
ip source-route
no ip icmp rate-limit unreachable
ip cef
!
!
!
!
no ip domain lookup
no ipv6 cef
!
multilink bundle-name authenticated
!
archive
 log config
  hidekeys
! 
ip tcp synwait-time 5
!
interface Loopback100
 ip address 100.100.100.1 255.255.255.0
!
interface Loopback200
 ip address 200.200.200.1 255.255.255.0
!
interface FastEthernet0/0
 no ip address
 shutdown
 duplex half
!
interface GigabitEthernet1/0
 ip address 10.10.10.1 255.255.255.252
 negotiation auto
!
interface GigabitEthernet2/0
 ip address 20.20.20.1 255.255.255.252
 negotiation auto
!
router bgp 5678
 no synchronization
 bgp log-neighbor-changes
 network 100.100.100.0 mask 255.255.255.0
 network 200.200.200.0
 neighbor 10.10.10.2 remote-as 1234
 neighbor 10.10.10.2 route-map gi1/0 out
 neighbor 20.20.20.2 remote-as 1234
 neighbor 20.20.20.2 route-map gi2/0 out
 no auto-summary
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!
ip prefix-list gi1/0 seq 5 permit 100.100.100.0/24 le 32
!
ip prefix-list gi2/0 seq 5 permit 200.200.200.0/24 le 32
!
route-map gi1/0 permit 10
 match ip address prefix-list gi1/0
!
route-map gi2/0 permit 10
 match ip address prefix-list gi2/0
!
control-plane
!
gatekeeper
 shutdown
!
!
line con 0
 exec-timeout 0 0
 privilege level 15
 logging synchronous
 stopbits 1
line aux 0
 exec-timeout 0 0
 privilege level 15
 logging synchronous
 stopbits 1
line vty 0 4
 login
!
end

Edge-Switch-R1

------------------------

!
upgrade fpd auto
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Edge-Switch
!
boot-start-marker
boot-end-marker
!
logging message-counter syslog
no logging console
!
no aaa new-model
ip source-route
no ip icmp rate-limit unreachable
ip cef
!
!
!
!
no ip domain lookup
no ipv6 cef
!
multilink bundle-name authenticated
!
archive
 log config
  hidekeys
! 
ip tcp synwait-time 5
!
interface FastEthernet0/0
 ip address 192.168.18.1 255.255.255.252
 duplex auto
 speed auto
!
interface FastEthernet0/1
 no ip address
 shutdown
 duplex auto
 speed auto
!
interface GigabitEthernet1/0
 ip address 10.10.10.2 255.255.255.252
 negotiation auto
!
interface GigabitEthernet2/0
 ip address 20.20.20.2 255.255.255.252
 negotiation auto
!
router eigrp 100
 redistribute bgp 1234 metric 100000 10000 255 255 1500 route-map bgp->eigrp
 network 192.168.18.0 0.0.0.3
 no auto-summary
!
router bgp 1234
 no synchronization
 bgp log-neighbor-changes
 redistribute eigrp 100
 neighbor 10.10.10.1 remote-as 5678
 neighbor 10.10.10.1 route-map community in
 neighbor 20.20.20.1 remote-as 5678
 no auto-summary
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!
ip bgp-community new-format
ip community-list 1 permit 10:20
!
route-map bgp->eigrp permit 20
 match community 1 exact-match
!
route-map eigrp->bgp permit 20
!
route-map community permit 10
 set community 10:20
!
control-plane
!
gatekeeper
 shutdown
!
!
line con 0
 exec-timeout 0 0
 privilege level 15
 logging synchronous
 stopbits 1
line aux 0
 exec-timeout 0 0
 privilege level 15
 logging synchronous
 stopbits 1
line vty 0 4
 login
!
end

INT-ASA (just the name, not really the ASA)

==========

version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname int-asa
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 5
no ip icmp rate-limit unreachable
!
!
ip cef
no ip domain lookup
!
ip tcp synwait-time 5
! 
interface Loopback1
 ip address 111.111.111.1 255.255.255.0
!
interface FastEthernet0/0
 ip address 192.168.18.2 255.255.255.252
 duplex auto
 speed auto
!
interface FastEthernet0/1
 no ip address
 shutdown
 duplex auto
 speed auto
!
!
router eigrp 100
 network 111.111.111.0 0.0.0.255
 network 192.168.18.0 0.0.0.3
 no auto-summary
!
no ip http server
no ip http secure-server
ip forward-protocol nd
!
control-plane
!
line con 0
 exec-timeout 0 0
 privilege level 15
 logging synchronous
line aux 0
 exec-timeout 0 0
 privilege level 15
 logging synchronous
line vty 0 4
 login
!
!
end

Route table o/p from all the routers:

----------------

Edge-Switch#sh ip bgp
BGP table version is 7, local router ID is 192.168.18.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 100.100.100.0/24 10.10.10.1               0             0 5678 i
*> 111.111.111.0/24 192.168.18.2        156160         32768 ?
*> 192.168.18.0/30  0.0.0.0                  0         32768 ?
*> 200.200.200.0    20.20.20.1               0             0 5678 i

Gateway of last resort is not set

B    200.200.200.0/24 [20/0] via 20.20.20.1, 00:15:40
     100.0.0.0/24 is subnetted, 1 subnets
B       100.100.100.0 [20/0] via 10.10.10.1, 00:15:57
     20.0.0.0/30 is subnetted, 1 subnets
C       20.20.20.0 is directly connected, GigabitEthernet2/0
     111.0.0.0/24 is subnetted, 1 subnets
D       111.111.111.0 [90/156160] via 192.168.18.2, 00:16:20, FastEthernet0/0
     10.0.0.0/30 is subnetted, 1 subnets
C       10.10.10.0 is directly connected, GigabitEthernet1/0
     192.168.18.0/30 is subnetted, 1 subnets
C       192.168.18.0 is directly connected, FastEthernet0/0

ISP#sh ip bgp
BGP table version is 7, local router ID is 200.200.200.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 100.100.100.0/24 0.0.0.0                  0         32768 i
*  111.111.111.0/24 20.20.20.2          156160             0 1234 ?
*>                  10.10.10.2          156160             0 1234 ?
*  192.168.18.0/30  20.20.20.2               0             0 1234 ?
*>                  10.10.10.2               0             0 1234 ?
*> 200.200.200.0    0.0.0.0                  0         32768 i

int-asa#sh ip route
 

Gateway of last resort is not set

     100.0.0.0/24 is subnetted, 1 subnets
D EX    100.100.100.0
           [170/2588160] via 192.168.18.1, 00:15:50, FastEthernet0/0
     111.0.0.0/24 is subnetted, 1 subnets
C       111.111.111.0 is directly connected, Loopback1
     192.168.18.0/30 is subnetted, 1 subnets
C       192.168.18.0 is directly connected, FastEthernet0/0

[Sunil Bhadauria · Accepted solution]

Yes , You can set community to all the ebgp routes being received by concerned neighbor using one route-map and then use this community to match desired prefixes under another route-map , this second route-map then further can be used while redistributing in OSPF .

Regards

Sunil Bhadauria