Cisco 2921 Router Load Balancing Configuration

[sylvester4u]

Hi,

    I am having Cisco 2921 router with two ISP. I want to configure load balancing between these ISP's with "load balancing per packet", but my VPN packets should super seed the load balancing configuration and should go only through primary ISP. Please guide me with the configuration.

Regards,

Rehan 

[Joseph W. Doherty]

"I want to configure load balancing between these ISP's with "load balancing per packet". . . "

Generally you want to (very much) avoid load balancing per packet. Instead, either statically load balance flows, per ISP, or consider using something like Cisco's PfR which can dynamically load balance flows, per ISP.

[Richard Burts]

Rehan 

I agree with Joseph that trying to load balance per packet can have unintended consequences and generally you want to stay away from per packet load balancing. The biggest problem is that with per packet balancing it increases the possibility of out of order packets and many applications do not handle out of order packets well.

But if we can look past that detail you asked a valid question of how to have VPN traffic always use one ISP while other traffic is load balanced. The solution for this would typically be to use Policy Based Routing. If your VPN is a Remote Access VPN then PBR could probably match on traffic for the VPN address pool. And if your VPN is site to site VPN then the ACL for PBR would probably match the logic of the ACL used in the crypto map.

HTH

Rick