02-08-2014 12:15 PM - edited 03-04-2019 10:17 PM
Hello All,
I'm trying to configure a Backbone running MPLS and BGP .. I've been able to establish MPLS between the routers. The PELeft and PERight will be connected to end routers where the end routers will be in separate VRFs (2 to be exact).
I have reachability between all the routers. I'm running OSPF in the Backbone between the 3 Routers, and BGP between PELeft and PERight.
Here are the configuration of the 3 Routers:
PELeft:
interface Loopback0
ip address 1.1.1.1 255.255.255.255
!
interface Serial0/0
ip address 10.10.10.2 255.255.255.0
mpls ip
clock rate 2000000
!
router ospf 1
log-adjacency-changes
network 1.1.1.1 0.0.0.0 area 0
network 10.10.10.0 0.0.0.255 area 0
!
router bgp 13879
bgp log-neighbor-changes
neighbor 2.2.2.2 remote-as 13879
!
address-family ipv4
neighbor 2.2.2.2 activate
no auto-summary
no synchronization
exit-address-family
CorePRouter:
interface Serial0/0
ip address 10.10.10.1 255.255.255.0
mpls ip
clock rate 2000000
!
router ospf 1
log-adjacency-changes
network 10.10.10.0 0.0.0.255 area 0
network 10.10.20.0 0.0.0.255 area 0
PERight:
interface Loopback0
ip address 2.2.2.2 255.255.255.255
!
interface Serial0/0
ip address 10.10.20.2 255.255.255.0
mpls ip
clock rate 2000000
!
router ospf 1
log-adjacency-changes
network 2.2.2.2 0.0.0.0 area 0
network 10.10.20.0 0.0.0.255 area 0
!
router bgp 13879
bgp log-neighbor-changes
neighbor 1.1.1.1 remote-as 13879
!
address-family ipv4
neighbor 1.1.1.1 activate
no auto-summary
no synchronization
exit-address-family
And for the reachability:
PERight#ping 1.1.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/25/76 ms
CorePRouter#sh mpls ldp n
Peer LDP Ident: 10.10.10.2:0; Local LDP Ident 10.10.20.1:0
TCP connection: 10.10.10.2.646 - 10.10.20.1.50623
State: Oper; Msgs sent/rcvd: 48/50; Downstream
Up time: 00:31:06
LDP discovery sources:
Serial0/0, Src IP addr: 10.10.10.2
Addresses bound to peer LDP Ident:
10.10.10.2 1.1.1.1
Peer LDP Ident: 10.10.20.2:0; Local LDP Ident 10.10.20.1:0
TCP connection: 10.10.20.2.12741 - 10.10.20.1.646
State: Oper; Msgs sent/rcvd: 47/47; Downstream
Up time: 00:31:03
LDP discovery sources:
Serial0/1, Src IP addr: 10.10.20.2
Addresses bound to peer LDP Ident:
10.10.20.2 2.2.2.2
Routes on All Routers:
CorePRouter:
CorePRouter#sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
1.0.0.0/32 is subnetted, 1 subnets
O 1.1.1.1 [110/65] via 10.10.10.2, 00:30:12, Serial0/0
2.0.0.0/32 is subnetted, 1 subnets
O 2.2.2.2 [110/65] via 10.10.20.2, 00:30:02, Serial0/1
10.0.0.0/24 is subnetted, 2 subnets
C 10.10.10.0 is directly connected, Serial0/0
C 10.10.20.0 is directly connected, Serial0/1
PERight:
PERight#sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
1.0.0.0/32 is subnetted, 1 subnets
O 1.1.1.1 [110/129] via 10.10.20.1, 00:27:28, Serial0/0
2.0.0.0/32 is subnetted, 1 subnets
C 2.2.2.2 is directly connected, Loopback0
10.0.0.0/24 is subnetted, 2 subnets
O 10.10.10.0 [110/128] via 10.10.20.1, 00:27:28, Serial0/0
C 10.10.20.0 is directly connected, Serial0/0
PELeft:
PELeft#sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
1.0.0.0/32 is subnetted, 1 subnets
C 1.1.1.1 is directly connected, Loopback0
2.0.0.0/32 is subnetted, 1 subnets
O 2.2.2.2 [110/129] via 10.10.10.1, 00:27:53, Serial0/0
10.0.0.0/24 is subnetted, 2 subnets
C 10.10.10.0 is directly connected, Serial0/0
O 10.10.20.0 [110/128] via 10.10.10.1, 00:27:53, Serial0/0
But the BGP between the PERight and PELeft is not coming up
PERight#sh ip bgp summ | b N
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
1.1.1.1 4 13879 0 0 0 0 0 never Active
PELeft#sh ip bgp summ | b N
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
2.2.2.2 4 13879 0 0 0 0 0 never Active
What am I missing here?
Solved! Go to Solution.
02-08-2014 12:25 PM
Hi Islam,
I believe you are missing the neighbor update-source commands in your BGP configuration.
PELeft should have:
router bgp 13879
neighbor 2.2.2.2 update-source Loopback0
and PERight should have:
router bgp 13879
neighbor 1.1.1.1 update-source Loopback0
I suspect that right now, your PELeft and PERight are trying to contact each other but they use ther IP addresses from serial interfaces as source IP addresses, and do not recognize each other under these addresses.
Try adding these commands to the configuration and give it a minute or so for the BGP peering to come up. If it does not help please post the output of show ip bgp neighbor from both PELeft and PERight. Thank you!
Best regards,
Peter
02-08-2014 12:25 PM
Hi Islam,
I believe you are missing the neighbor update-source commands in your BGP configuration.
PELeft should have:
router bgp 13879
neighbor 2.2.2.2 update-source Loopback0
and PERight should have:
router bgp 13879
neighbor 1.1.1.1 update-source Loopback0
I suspect that right now, your PELeft and PERight are trying to contact each other but they use ther IP addresses from serial interfaces as source IP addresses, and do not recognize each other under these addresses.
Try adding these commands to the configuration and give it a minute or so for the BGP peering to come up. If it does not help please post the output of show ip bgp neighbor from both PELeft and PERight. Thank you!
Best regards,
Peter
02-08-2014 12:38 PM
Thank You! This is what I was missing!
02-08-2014 12:41 PM
Hi Islam,
It has been a pleasure. Take care!
Best regards,
Peter
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