Hi Guys,
I’m labbing out trying to modify path attributes. However, I can’t seem to get past the issue being this:
My loopback from an iBGP router(1.1.1.1) can reach the eBGP loopback and physical interface IPs from a different AS(200).
Here is my simple diagram below:
Here are my configurations:
R1
router ospf 100
network 0.0.0.0 255.255.255.255 area 0
!
router bgp 100
bgp router-id 1.1.1.1
bgp log-neighbor-changes
network 1.1.1.0 mask 255.255.255.0
neighbor 2.2.2.2 remote-as 100
neighbor 2.2.2.2 update-source Loopback0
neighbor 3.3.3.3 remote-as 100
neighbor 3.3.3.3 update-source Loopback0
!
=======================================
R2
router ospf 100
network 0.0.0.0 255.255.255.255 area 0
!
router bgp 100
bgp router-id 2.2.2.2
bgp log-neighbor-changes
neighbor 1.1.1.1 remote-as 100
neighbor 1.1.1.1 update-source Loopback0
neighbor 1.1.1.1 next-hop-self
neighbor 3.3.3.3 remote-as 100
neighbor 3.3.3.3 update-source Loopback0
neighbor 4.4.4.4 remote-as 200
neighbor 4.4.4.4 ebgp-multihop 2
!
ip route 4.4.4.0 255.255.255.0 192.168.1.2
!
==========================================
R3
router ospf 100
network 0.0.0.0 255.255.255.255 area 0
!
router bgp 100
bgp router-id 3.3.3.3
bgp log-neighbor-changes
neighbor 1.1.1.1 remote-as 100
neighbor 1.1.1.1 update-source Loopback0
neighbor 1.1.1.1 next-hop-self
neighbor 2.2.2.2 remote-as 100
neighbor 2.2.2.2 update-source Loopback0
neighbor 4.4.4.4 remote-as 200
neighbor 4.4.4.4 ebgp-multihop 2
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!
ip route 4.4.4.0 255.255.255.0 172.16.1.2
!
=============================================
R4
router bgp 200
bgp router-id 4.4.4.4
bgp log-neighbor-changes
network 8.8.8.0 mask 255.255.255.0
network 9.9.9.0 mask 255.255.255.0
neighbor 2.2.2.2 remote-as 100
neighbor 2.2.2.2 ebgp-multihop 2
neighbor 2.2.2.2 update-source Loopback0
neighbor 3.3.3.3 remote-as 100
neighbor 3.3.3.3 ebgp-multihop 2
neighbor 3.3.3.3 update-source Loopback0
!
ip route 2.2.2.0 255.255.255.0 192.168.1.1
ip route 3.3.3.0 255.255.255.0 172.16.1.1
!
Here are my traceroute results from R1 trying to get to R4’s interface IP as well as the loopbacks:
Is the iBGP split horizon the culprit?
Any help will be greatly appreciated!
KB