BGP Confederation Questions

davidcriollo · ‎08-26-2023

Hi Everyone,

I have this topology, I'm not sure why R3 can not ping 10.1.1.1, Attached as much configuration that I deems is necesary. Please If you needs any other aditional information let me know.

R3

R3#show ip route
Codes: L - local, 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, H - NHRP, l - LISP
+ - replicated route, % - next hop override

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 11 subnets, 3 masks
B 10.1.1.0/24 [200/0] via 10.23.1.1, 00:01:35
B 10.7.7.0/24 [200/0] via 10.67.1.2, 00:14:13
O 10.7.7.1/32 [110/193] via 10.34.1.2, 01:20:11, Serial1/2
C 10.23.1.0/30 is directly connected, Serial1/1
L 10.23.1.2/32 is directly connected, Serial1/1
O 10.25.1.0/30 [110/128] via 10.23.1.1, 00:13:21, Serial1/1
C 10.34.1.0/30 is directly connected, Serial1/2
L 10.34.1.1/32 is directly connected, Serial1/2
O 10.46.1.0/30 [110/128] via 10.34.1.2, 01:21:56, Serial1/2
O 10.56.1.0/30 [110/192] via 10.34.1.2, 01:21:36, Serial1/2
[110/192] via 10.23.1.1, 00:13:21, Serial1/1
O 10.67.1.0/30 [110/192] via 10.34.1.2, 01:21:36, Serial1/2

R3#show bgp ipv4 unicast
BGP table version is 7, local router ID is 10.34.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

Network Next Hop Metric LocPrf Weight Path
*>i 10.1.1.0/24 10.23.1.1 0 100 0 100 i
*>i 10.7.7.0/24 10.67.1.2 0 100 0 (65200) 300 i

R3#show running-config | sec bgp
router bgp 65100
bgp log-neighbor-changes
bgp confederation identifier 200
neighbor 10.23.1.1 remote-as 65100
neighbor 10.23.1.1 route-reflector-client
neighbor 10.34.1.2 remote-as 65100
neighbor 10.34.1.2 route-reflector-client

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

R2

R2#show running-config | sec bgp
router bgp 65100
bgp log-neighbor-changes
bgp confederation identifier 200
bgp confederation peers 65200
neighbor 10.12.1.1 remote-as 100
neighbor 10.23.1.2 remote-as 65100
neighbor 10.23.1.2 next-hop-self
neighbor 10.25.1.2 remote-as 65200
neighbor 10.25.1.2 next-hop-self

R2#show runn
R2#show running-config | sec bgp
router bgp 65100
bgp log-neighbor-changes
bgp confederation identifier 200
bgp confederation peers 65200
neighbor 10.12.1.1 remote-as 100
neighbor 10.23.1.2 remote-as 65100
neighbor 10.23.1.2 next-hop-self
neighbor 10.25.1.2 remote-as 65200
neighbor 10.25.1.2 next-hop-self
R2#
R2#
R2#
R2#
R2#
R2#sho
R2#show ip route
Codes: L - local, 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, H - NHRP, l - LISP
+ - replicated route, % - next hop override

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 13 subnets, 3 masks
B 10.1.1.0/24 [20/0] via 10.12.1.1, 00:10:21
B 10.7.7.0/24 [200/0] via 10.67.1.2, 00:10:23
O 10.7.7.1/32 [110/193] via 10.25.1.2, 00:22:07, Serial1/2
C 10.12.1.0/30 is directly connected, Serial1/0
L 10.12.1.2/32 is directly connected, Serial1/0
C 10.23.1.0/30 is directly connected, Serial1/1
L 10.23.1.1/32 is directly connected, Serial1/1
C 10.25.1.0/30 is directly connected, Serial1/2
L 10.25.1.1/32 is directly connected, Serial1/2
O 10.34.1.0/30 [110/128] via 10.23.1.2, 00:22:24, Serial1/1
O 10.46.1.0/30 [110/192] via 10.25.1.2, 00:22:07, Serial1/2
[110/192] via 10.23.1.2, 00:22:24, Serial1/1
O 10.56.1.0/30 [110/128] via 10.25.1.2, 00:22:07, Serial1/2
O 10.67.1.0/30 [110/192] via 10.25.1.2, 00:22:07, Serial1/2
R2#
R2#
R2#sho
R2#show bgp ipv4 uni
BGP table version is 3, local router ID is 10.25.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

Network Next Hop Metric LocPrf Weight Path
*> 10.1.1.0/24 10.12.1.1 0 0 100 i
* 10.7.7.0/24 10.67.1.2 0 100 0 (65200) 300 i
*>i 10.67.1.2 0 100 0 (65200) 300 i

M02@rt37 · ‎08-26-2023

Hello @davidcriollo,

Does R1 know the route towards 10.34.1.0/30 ?

Best regards
.ı|ı.ı|ı. If This Helps, Please Rate .ı|ı.ı|ı.

Flavio Miranda · ‎08-26-2023

@davidcriollo

R2 can ping 10.1.1.1?

Does not forget that R1 and R2 are forming eBGP and you are trying to ping a loopback. Make sure you dont need the ebgp-multihop

davidcriollo · ‎08-28-2023

Yes, R1 did not know a router for any ip address in AS200 or AS300, I configure a default route and it went through. however, is that a good practice? or which will be the best option so r1 can learn router from AS200 or AS300?

Flavio Miranda · ‎08-28-2023

The problem rely on the fact that you are using eBGP and trying to reach loopback. There is nothing wrong with that and that is nothing wrong to use static/deffault route. It is just a matter of what you want to accomplish and how.

If static route fix your problem, then that´s fine.