ASA Load Sharing to Single ISP

Unanswered Question
Aug 19th, 2009
User Badges:

Hi all,

I have read through countless posts on my question and have gleaned a lot of information from them.

My scenario is this.

We have a 6500 core connected to two ASA's in active/standby mode. The ASAs are connected to two 3550 switches which are providing BGP pairing with each other and our ISPs Internet links, both 1Gb/s one to each switch, running as primary/backup. The ASA has a default route to the HSRP address shared by the switches.

We have cause to allocate a subnet from our range to a third party temporarily. I would like to route this subnet through the backup link (outgoing and incoming)

I can configure BGP to route accordingly, but this will only apply for incoming traffic.

I could put a route-map on on of the 3550's to reroute traffic based on source ip to use the other switch/backup link, but this will waste bandwidth on the switch interface.

Any other ideas how I can push one subnet out of one switch, and the rest through the other?

Many thanks for reading,


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Collin Clark Wed, 08/19/2009 - 05:19
User Badges:
  • Purple, 4500 points or more

You could use the weight attribute in BGP to influence that route to go out the backup circuit. You will have to configure it using a route map so only the specific route gets weighted. I think a static route would work too. Since the ASA does not support PBR, I don't think it's possible there.


This Discussion