Need help in BGP peer group configuration

[Gopinath_Pigili]

I am  configuring BGP peer group.......I did the required configuration...

When I give the

show bgp ipv4 unicast summary.....iBGP neigbors(in peer group)

are in "never" state.....

I configured ospf in AS-100 and all loopbacks are reachable.....

I am sharing the topology and configuration...Please help me to fix this problem...

R1(config)# router bgp 100
R1(config-router)# no bgp default ipv4-unicast
R1(config-router)# neighbor Group1 peer-group
R1(config-router)# neighbor Group1 remote-as 100
R1(config-router)# neighbor Group1 update-source loopback 0
R1(config-router)# neighbor 10.1.12.2 peer-group Group1
R1(config-router)# neighbor 10.1.13.3 peer-group Group1
R1(config-router)# neighbor 10.1.14.4 peer-group Group1
R1(config-router)# neighbor 11.1.15.5 remote-as 200
R1(config-router)# address-family ipv4 unicast
R1(config-router-af)# neighbor 10.1.12.2 activate
R1(config-router-af)# neighbor 10.1.13.3 activate
R1(config-router-af)# neighbor 10.1.14.4 activate
R1(config-router-af)# neighbor 11.1.15.5 activate
R1(config-router-af)# network 1.1.1.1 mask 255.255.255.255
R1(config-router-af)# end

R2(config)# router bgp 100
R2(config-router)# no bgp default ipv4-unicast
R2(config-router)# neighbor Group1 peer-group
R2(config-router)# neighbor Group1 remote-as 100
R2(config-router)# neighbor Group1 update-source loopback 0
R2(config-router)# neighbor 10.1.12.1 peer-group Group1
R2(config-router)# neighbor 10.1.13.3 peer-group Group1
R2(config-router)# neighbor 10.1.14.4 peer-group Group1
R2(config-router)# address-family ipv4 unicast
R2(config-router-af)# neighbor 10.1.12.1 activate
R2(config-router-af)# neighbor 10.1.13.3 activate
R2(config-router-af)# neighbor 10.1.14.4 activate
R2(config-router-af)# network 2.2.2.2 mask 255.255.255.255
R2(config-router-af)# end

R3(config)# router bgp 100
R3(config-router)# no bgp default ipv4-unicast
R3(config-router)# neighbor Group1 peer-group
R3(config-router)# neighbor Group1 remote-as 100
R3(config-router)# neighbor Group1 update-source loopback 0
R3(config-router)# neighbor 10.1.13.1 peer-group Group1
R3(config-router)# neighbor 10.1.12.2 peer-group Group1
R3(config-router)# neighbor 10.1.14.4 peer-group Group1
R3(config-router)# address-family ipv4 unicast
R3(config-router-af)# neighbor 10.1.13.1 activate
R3(config-router-af)# neighbor 10.1.12.2 activate
R3(config-router-af)# neighbor 10.1.14.4 activate
R3(config-router-af)# network 3.3.3.3 mask 255.255.255.255
R3(config-router-af)# end

R4(config)# router bgp 100
R4(config-router)# no bgp default ipv4-unicast
R4(config-router)# neighbor Group1 peer-group
R4(config-router)# neighbor Group1 remote-as 100
R4(config-router)# neighbor Group1 update-source loopback 0
R4(config-router)# neighbor 10.1.14.1 peer-group Group1
R4(config-router)# neighbor 10.1.13.3 peer-group Group1
R4(config-router)# neighbor 10.1.12.2 peer-group Group1
R4(config-router)# address-family ipv4 unicast
R4(config-router-af)# neighbor 10.1.14.1 activate
R4(config-router-af)# neighbor 10.1.13.3 activate
R4(config-router-af)# neighbor 10.1.12.2 activate
R4(config-router-af)# network 4.4.4.4 mask 255.255.255.255
R4(config-router-af)# end

[MHM Cisco World]

I dont see anything wrong with group but are LO is reachable' you use lo as update source and it must be reachable to make bgp session up.

[Gopinath_Pigili]

I configured ospf in AS-100 and all loopback are reachable....

[MHM Cisco World]

Can I see

show ip route

in each router R1'2'3'4

[Martin L · Accepted solution]

yes, but u are not using loopbacks in your neighbor statements;  this will also work without ospf. try it. 

neighbor 10.1.1x.y xyz

- no ospf needed since those are directly connected networks/IPs. however, i u use

neighbor 2.2.2.2 xyz

then u need routing to it, either ospf or static routes.

Regards, ML
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[MHM Cisco World · Accepted solution]

You use LO' so you need 

Ospf and make sure rechability 

You need to use LO as neighbor in all router in as100.

No need router reflect you have already full mesh.

MHM

[Gopinath_Pigili · Accepted solution]

Yes.... I replaced neighbor statements with loopback addresses in all routers in AS-100.

Now...it's working ......

R1(config)# router bgp 100
R1(config-router)# no bgp default ipv4-unicast
R1(config-router)# neighbor Group1 peer-group
R1(config-router)# neighbor Group1 remote-as 100
R1(config-router)# neighbor Group1 update-source loopback 0
R1(config-router)# neighbor 2.2.2.2 peer-group Group1
R1(config-router)# neighbor 3.3.3.3 peer-group Group1
R1(config-router)# neighbor 4.4.4.4 peer-group Group1
R1(config-router)# neighbor 11.1.15.5 remote-as 200
R1(config-router)# address-family ipv4 unicast
R1(config-router-af)# neighbor 2.2.2.2 activate
R1(config-router-af)# neighbor 3.3.3.3 activate
R1(config-router-af)# neighbor 4.4.4.4 activate
R1(config-router-af)# neighbor 11.1.15.5 activate
R1(config-router-af)# end

Thanks for the response....

[Martin L]

I think i have notes for this group-peer thing.... stay tune. However, one thing to point out from config right now u have

neighbor Group1 update-source loopback 0

but IP is not loopback ; it is connected interface IP in

neighbor 10.1.12.2 peer-group Group1

once u remove

update-source loopback 

command , u will see changes. Except R1, u still will have "never" state on spokes.  this is because spoke to spoke

ping

fails; Also, R1 should be Route-reflector.  U could remove extra neighbor statements from spokes.

Alternative option is to change IP to actual loopback 0 in your neighbor statements, this is

neighbor Lopback0  peer-group Group1

and keep

neighbor Group1 update-source loopback 0

. Here, I think this would make full-mesh topo so route reflector is not needed.

I would recommend using R1 as a route-reflector. I think u should. right ? otherwise spokes will not have all routes, only R1 will.

Regards, ML
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