High Availability Pair two Cisco 2811 Routers

Unanswered Question
Aug 4th, 2009

At a number of our sites we have two 2811 routers, each with 2 ADSL WIC cards.

Do 2811 routers support any HA protocols?To provide connectivity for the PC's we a 3750 switch which each router connects to. The PC's default gateway is set to the router interface which connects to the switch therefore if the router were to fail there would be no automatic failover.

I would also like to load balance across each router?

Is this possible?


I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Wilson Samuel Tue, 08/04/2009 - 07:10


For Fault Tolerance I gues the best bet would be to go ahead with HSRP/VRRP. It will certainly make it possible for you to make it seamlessly failover to the backup once the primary link/router fails.

However if you want to load balance, its a whole together different challange.

Please let me know how much is the need for the load balance across the routers


Wilson Samuel

John Blakley Tue, 08/04/2009 - 07:13


You should look into HSRP, VRRP, or GLBP for the router's redundancy for the clients. All of the above protocols present a virtual ip address that the clients will use as their gateway. For example, if you use HSRP, there will be a primary and standby router. All traffic will go out of the primary as long as it's up, but if it goes down, the standby will take over the role of the primary, but the clients won't know that it happened because their gateway is the virtual ip address.

GLBP is the only different protocol above because it does load balancing. Per your last requirement, that will probably be the protocol that you'll want to look into:




darrenriley5 Tue, 08/04/2009 - 07:35


At the moment we have static routes for from router 1 to router 2 which routes certain traffic down router 2. We NAT this traffic so it returns the same way.

I'd like to get away from this. The other day we had a router fail but we had no automatic failover, we had to use a manual process which meant the site was out of action for a while until we made the changes to route the traffic via the operational router.

I'll look in to GLBP.


This Discussion