Can I Load balance across parallel VPN tunnels w/GRE?

[Randall White]

Hi All,

How can I load balance (per destination) across two IPSec VPNs? My main site is dual homed to the Internet w/ two routers (one router per ISP). The remote sites have either a single router or a single PIX. I would like to run GRE over IPSec with OSPF for fast failover. Will this setup also load balance?

Any links or info is appreciated!

Thanks, Randy

[gmiiller]

The answer is yes you can load balance over multiple GRE tunnels, and yes you can run load balancing by means of your routing protocol. Most implementations I have seen have used EIGRP. Things to keep in mind are that as you say, load balancing should probably be per destination not per packet.

If your load-balancing is not needed to be entirely even, you may be better off to adjust routing behaviour so that remote sites favour one gateway router or the other. This can simplify troubleshooting.

If you aren't using multipoint GRE, you could also consider this with your two main routers as NHS's. Only issue that you will have is the lack of GRE support on the Pix's