Route-Reflector - Next-Hop

[adirinaldi]

I have a problem configuring Route-Reflector in the following scenario.

Diagram:

R1-AS100 === R2-AS200 --- R3-AS200 --- R4-AS200 --- R5-AS200 --- R6-AS200 === R7-AS300

Legend (for diag above):

R1-AS100 --> Router 1; BGP AS100

=== --> eBGP peer

--- --> iBGP peer

Scenario 1:

# R3 as an RR (R2 & R4 client to R3).

# R5 as an RR (R6 client to R5).

# R3 & R5 = iBGP peer.

Problem 1:

1. I used Route-Map in R3 to point to R2 as a next hop. but the result is R4 now point to R2 as a next-hop, thus create a black hole in R3. Same result when i used next-hop-self on R2 & R6.

!Sample Route-map from R3

route-map TO-R2 permit

set ip next-hop <R2 address>

router bgp 200

neigh <R2 address> route-map TO-R5 in

The question is how do i solve next-hop issue in this scenario. any help would be much appreciate, Thank you.

~AR~

[Harold Ritter]

First, you should not change the next hop of the reflected prefixes on the RR.

Second, I do not see how you create a black hole on R3 by using next-hop-self on R2 and R6. R3 should have R2 as the next hop for routes learnt from R2. So will R4.

Do you have an iBGP session between R3 and R5?

Could you please explain further.

[adirinaldi]

On the first time,

I tried to modify next-hop because R4 still point to R1 as next-hop (instead of R3)

and i have read that RR does not reflect next-hop from next-hop-self command. So how do i change the next hop (for example in R4)

And yes, i have an iBGP peer session between R3 & R5.

Regards,

~AR~

PS: Thanks for spends your time reading this.

[Harold Ritter]

The next-hop-self should be applied on R2 and R6. The RR is not the place to change the next hop.

Next-hop-self on the RR will work for eBGP received prefixes on the RR.

Hope this helps,

[pushkar1782]

Hi

Accordingly if you need to pass routes from R3 to R5 ( in ibgp ) and you

1) have made R3 as RR -- is R5 a client of R3 ??

router bgp xxx

neighbor route-reflector-client

2) if you make R5 as RR again so R3 should be the client for R5 ...

router bgp xxx

neighbor route-reflector-client

some document to support . :::

The bgp client-to-client reflection command controls client-to-client reflection

http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/ip_c/ipcprt2/1cdbgp.htm#wp1001965

=========================================

can you paste the relevant config. that would greatly help in troubleshooting

1) what is the exit point for AS200 is it R2 or R3 after u made it RR ??

< rate if helps >

[mark.edwards]

Hi, Can you not just advertise the eBGP links into your IGP? This would be the simple solution (do the same for the R6-R7 link as well). It is notmal to see the eBGP link as next hop address.