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Cisco HSRP

Is it possible to configure 2 cisco routers to run HSRP over WAN links (located at 2 distant cities) so that redundancy of the routers can be established?

CoccoBill

I believe that's exactly what it's meant for?

http://www.cisco.com/univercd/cc/td/doc/cisintwk/ics/cs009.htm

tozden

ASKER

You can refer the following diagram: HOST uses Redundant R1 (active) router to access internet and switch to the Redundant R2 in case of a problem in R1.

Host INTERNET INTERNET
| | |
Ethernet-----Redundant R1 (active) Redundant R2 (stndby)
| |
|---WAN Router1 ------------------------WAN Router2-----Ethernet

As far as I understood; HSRP is a redundancy mechanishm designed for local LAN's (e.g. ethernet) based on the ARP replies..

My aim is to understand whether such a solution is possible by use of HSRP (routers located in distant cities); actually I do not want to implement this as as solution.

ECNSSMT

The heartbeat between the two routers would have to be unobstructed; and If I recall correctly its a layer 2 frame. So, I suppose, if there were no intermediary routers, it is possible. The only thing would be that, it may not be practical depending on your subnet scheme. With HSRP you are providing a path to a virtual router (IP Address/virtual gateway), which the all network devices have to use to egress your network into the internet. If the two routers were on the same subnet it would be do-able. But a single subnet across a WAN also implies broadcast across the WAN connection (this is the only noteworthy issue I can think of now, but then again I'm still waking up).

Also note that there are other routing schemes that can ensure internet connectivity that can be used. (and for the life of me I can't think of them right now).

Regards,

ASKER CERTIFIED SOLUTION

grsteed

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tozden

ASKER

Dear all;

Thank you very much for your contributions. I have been satisfied by the answers; the HSRP is can be implemented within the same broadcast domain as I have known. Although it is not very effective, I think it is possible to implement my question design by use of VPLS or some other technique.

Unfortunately I had to select only one of the answers; I think the point are deserved by Gary with the careful answer and configurations.
Regards;

grsteed

Thanks, glad I could help.

Gary