BGP Failover between two ISP routers : ibgp

[choylee]

Hello,

I have two ISP with theirs own AS numbers.

I have my own AS and my IP addresses in PI (provider independente)

I am not in full table mode but I receive the default route of each of my ISP.

So I can see that :

On the primary router R1 :

B*    0.0.0.0/0 [20/0] via A.A.A.A, 00:00:26

On the secondary R2 :

B*    0.0.0.0/0 [200/0] via B.B.B.B, 00:2:26

ISP_1         ISP_2

   |                  |

   | eBGP        |eBGP

   |                  |

   |     iBGP     |

  R1--------------R2

   |                  |

          LAN

Now, I receive the inbound traffic from ISP_1 and ISP_2 ( As-prepends politics.....)

I send the oubound traffic on the ISP_2.

My issue :

If my session external BGP is down between  ISP_2 ans R2

then my traffic doesn't forward to R01 (iBGP) in order to go out the ISP_1

The update of ISP2  is set with "local-preference 110" on my r2

The update of ISP1 is "set local-preference 100" on my r1

Is there a tip to automatic failover ?

Many Thanks

[Reza Sharifi]

Hi,

You failover should be automatic. For your outgoing traffic, you have a local-pref of 110 on r2, which makes it the primary router to get to the outside.

When the link between r2 and ISP-2 fails, the traffic should go to r1 and out to ISP-1.

Here is a document with config examples to look at:

http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a00800945bf.shtml#conf5

HTH

Reza

[choylee]

Thanks a lot !!

In fact , I forgot the "next-hop-self" in my configuration

So, the default route from r2 was not understood by r1 because itmay not necessarily have a route to that source address of ISP.

Now, I am going to test automatic failover