BGP Help

[Matt Cooper]

Looking for some assistance in my BGP configuration. I have a peer (172.26.10.10) not coming up. I have a small porition of the config, let me know if you need more. I've also posted the logs of what i'm getting when i bring up gi0/0/0.129. I have two circuits, on the second one, I put in a remote-as.. Am I missing something in BGP?

show ip bgp sum

172.26.10.6 4 13979 8034 8880 1976 0 0 5d13h 222
172.26.10.10 4 13979 0 0 1 0 0 never Idle

*Apr 29 19:56:27.701: %BGP-5-NBR_RESET: Neighbor 172.26.10.10 active reset (Peer closed the session)
*Apr 29 19:56:27.701: %BGP_SESSION-5-ADJCHANGE: neighbor 172.26.10.10 IPv4 Unicast topology base removed from session Peer closed the session
*Apr 29 19:56:36.357: %BGP-3-NOTIFICATION: received from neighbor 172.26.10.10 active 2/2 (peer in wrong AS) 4 bytes 0000FDF2
*Apr 29 19:56:36.357: %BGP-5-NBR_RESET: Neighbor 172.26.10.10 active reset (BGP Notification received)
*Apr 29 19:56:36.357: %BGP-5-ADJCHANGE: neighbor 172.26.10.10 active Down BGP Notification received

interface Loopback0
ip address 32.252.192.239 255.255.255.255
!
interface GigabitEthernet0/0/0
no ip address
negotiation auto
!
interface GigabitEthernet0/0/0.716
encapsulation dot1Q 716
ip address 172.26.10.5 255.255.255.252
no ip redirects
no ip proxy-arp
no cdp enable
!
interface GigabitEthernet0/0/1
no ip address
negotiation auto
!
interface GigabitEthernet0/0/1.200
encapsulation dot1Q 200
ip address 192.168.1.3 255.255.255.0
no cdp enable
!
interface GigabitEthernet0/0/1.1000
encapsulation dot1Q 1000
ip address 172.18.2.4 255.255.255.0
!
interface GigabitEthernet0/0/2
no ip address
negotiation auto
!
interface GigabitEthernet0/0/2.129
encapsulation dot1Q 129
ip address 172.26.10.9 255.255.255.252
no ip redirects
no ip proxy-arp
no cdp enable
!
interface GigabitEthernet0/0/2.1000
no cdp enable
!
interface Serial0/1/0:23
encapsulation hdlc
isdn switch-type primary-ni
isdn bchan-number-order ascending
no cdp enable
!
interface Service-Engine0/4/0
!
interface GigabitEthernet0
vrf forwarding Mgmt-intf
no ip address
shutdown
negotiation auto
!
router bgp 65010
synchronization
bgp log-neighbor-changes
network 192.168.0.0
network 192.168.1.0
network 192.168.2.0
network 192.168.3.0
neighbor 172.26.10.6 remote-as 13979
neighbor 172.26.10.6 description EVPN HI
neighbor 172.26.10.10 remote-as 13979
!
ip forward-protocol nd
no ip http server
no ip http secure-server
ip route 0.0.0.0 0.0.0.0 10.38.67.240
ip route 192.168.0.0 255.255.255.0 192.168.1.2
ip route 192.168.1.0 255.255.255.0 192.168.1.2
ip route 192.168.2.0 255.255.255.0 192.168.1.2
ip route 192.168.3.0 255.255.255.0 192.168.1.2
ip route 192.168.4.0 255.255.255.0 172.26.10.17
ip route 192.168.5.0 255.255.255.0 172.26.10.17
ip route 192.168.6.0 255.255.255.0 172.26.10.17
ip route 192.168.12.0 255.255.255.0 172.26.10.13
!
!

Thanks!

Matt

[milan.kulik]

Hi,

are you saying you need to peer to two eBGP neighbors using AS# 65010 while peering to the neighbor 172.26.10.6 but AS# 65020 while peering to the neighbor 172.26.10.10?

Why don't you agree with ATT to use the same AS# on your router for both peerings?

If not possible, you could use

neighbor 172.26.10.10 local-as 65020 replace-as no-prepend

command to pretend your router running the AS# 65020 towards the neighbor 172.26.10.10.

See http://lostintransit.se/2012/08/13/bgp-local-as-command/

or command reference for more details.

Best regards,

Milan

[Matt Cooper]

I've asked AT&T if they could change. There is only 1 router. 

my current iOS doesn't support that command listed.

[Borgenstrand]

My knowledge of BGP is not great, I am studying BGP at the moment. From what I was reading, if you have a redundant connection to a neighbor, you cannot neighbor to both the IPs on the other side as it is the same router. BGP will not allow two or more neighborships with the same router. 

If you have two connections between two routers, you need to neighbor to their loopback IP instead. If you do that, you need to add this command in router BGP config. 

neighbor 11.11.11.11 ebgp-multihop 2

Please just change the 11.11.11.11 IP address to the other routers loopback IP address.

Do you have a loopback address of the other router?

[Matt Cooper]

Well, I guess I have determined my issue. The router itself can only route 1 ASN, to have two AVPN connections, I would need two routers in place.

[Yaron Golan]

Accomplish these commands :

- show ip cef 172.26.10.10

- ping 172.26.10.10 source 172.26.10.9

- give us the configuration of the other router .

Show the results please.