BGP Routing Problem

[crumdub12]

I have setup iBGP between three routers, but does not work unless I have a static route on the 2600 and AS5350 pointing to the 7609, the BGP setup seems correct, can you see any problems.

Here is setup:

AS5350:

router bgp 65534

no synchronization

bgp log-neighbor-changes

neighbor 192.168.230.162 remote-as 65534

neighbor 192.168.230.162 send-community

no auto-summary

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

2600:

router bgp 65534

bgp log-neighbor-changes

neighbor 192.168.230.130 remote-as 65534

neighbor 192.168.230.130 send-community

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

7609:

router bgp 65534

no synchronization

bgp log-neighbor-changes

neighbor 190.168.200.218 remote-as 64512

neighbor 190.168.200.218 send-community

neighbor 190.168.200.222 remote-as 64512

neighbor 190.168.200.222 send-community

neighbor 190.168.201.218 remote-as 64514

neighbor 190.168.201.218 send-community

neighbor 190.168.201.222 remote-as 64514

neighbor 190.168.201.222 send-community

neighbor 192.168.230.129 remote-as 65534

neighbor 192.168.230.129 send-community

neighbor 192.168.230.161 remote-as 65534

neighbor 192.168.230.161 send-community

no auto-summary

[Kevin Dorrell]

If you don't put the static routes on the AS5350 and 2600, do they still have "connected" routes to the 7609?

What sort of interfaces are between them? Are you sure you haven't simply got the cables reversed at the 7609? You could check with a show cdp neighbor.

If the partners are directly connected, why do you need the no synchronization?

Kevin Dorrell

Luxembourg

[crumdub12]

Kev,

I have static routes on the 7609 (Aggregation Router) here they are.

ip route 0.0.0.0 0.0.0.0 172.16.8.2

ip route 0.0.0.0 0.0.0.0 190.168.200.214

If I am connected to 7609, and I have static routes in, I can see SH IP BGP ,and PING, TELNET etc.. the 2600/as5350.

When I CLEAR IP BGP * , and delete static routes, I lose connection to 2600 AND AS5350.

The connections on 7609 are FastEthernet, the subnets are .252, so if cables crossed, no communication.

The NO SYNC was added by default, I will take it out.

[crumdub12]

Kev,

Apologies , my mistake.

The static routes are added on 2600 pointing to 7609, and AS5350 to 7609.This is route on 2600.

.I.E ip route 0.0.0.0 0.0.0.0 192.168.230.130

When I take off route, I can still ping .130,

(7609 I/F) , but not 192.168.230.162 (7609 I/F for AS5350). The subnet is 255.255.255.248 on both connections.

[Georg Pauwen]

Hello,

first of all, your three routers are in the same AS, but they are not fully meshed. You could configure the 7609 as a route reflector:

neighbor 192.168.230.129 remote-as 65534

neighbor 192.168.230.129 send-community

--> neighbor 192.168.230.129 route-reflector-client

neighbor 192.168.230.161 remote-as 65534

neighbor 192.168.230.161 send-community

--> neighbor 192.168.230.161 route-reflector-client

Also, before any BGP connectivity can be established, you need TCP connectivity between your routers. Can your routers ping each other without adding the static routes ?

Regards,

GP

[crumdub12]

The static routes are added on 2600 pointing to 7609, and AS5350 to 7609.This is route on 2600.

.I.E ip route 0.0.0.0 0.0.0.0 192.168.230.130

When I take off route, I can still ping .130,

(7609 I/F) , but not 192.168.230.162 (7609 I/F for AS5350). The subnet is 255.255.255.248 on both connections.

[Kevin Dorrell]

Now I drew the topology on paper, it is clearer. I'm afraid I don't have much experience in BGP yet, but I'll do my best.

So I take it that the routing table on the 2600 does not get a specific route to 192.168.230.160/29, and the routing table in the AS5350 does not get a specific route to 192.168.230.128/29.

I think Georg is right that the 7609 needs to be a route reflector.

If you want to ping the "other link", do you have any network commands on the routers to get the links advertised? Not sure whether these are necessary, but e.g. on the 7609.

network 192.168.230.160 mask 255.255.255.248

network 192.168.230.128 mask 255.255.255.248

Sorry if I'm sinking, but I'm still learning to swim!

Kevin Dorrell

Luxembourg

[crumdub12]

Kev,

Am in same boat , but we will learn BGP together !!!

Am adding the reflectors, and am also finishing the cabling to fully mesh the network, will get back to you with a response soon.

Slan / Ed

[swyka]

If you are going to use a reflector, I would strongly suggest that you static your BGP router ID(s). You don't want your reflector to re-elect its router ID by interface-IP and choose a different one.

[crumdub12]

A Chairde,

Just to finish off this, no matter what BGP settings I put on routers, when I pulled static routes out, they stopped connecting to 7609.

Looks Like I am stuck with them !!!

Thanks for all your help.....

[mjoaquin23]

try using loopback addresses for neighbor establishment. then use neigh x.x.x.x update-souce loopback-int. then neigh x.x.x.x next-hop-self. then redistribute all connected or necessary routes outside IBGP.

[paul driver]

Hello

bgp relies on NLRI for successful peering and especially ibgp which requires this to accommodate bgp synchroniszation rule 

although RR as already suggested is a possible choice I would apply and simple igp such as rip for NLRI between the routers in as65534 for anfull mesh ibgp configuration turn off sychronisation if you e hadn't done this and lastly the next hop self command between the internal ibgp peers 

res

paul