c1841 with 877 Standby Failover

simoncroak · ‎12-11-2008

Hi Guys,

My current setup:

I have a remote site that has a cisco 1841 router setup to be the primary router and a cisco 877 ADSL modem /router setup as a standby.

The issue:

The 1841 has 2 leased lines connected and it is configured so that if both leased lines fail the 877 backup will become the active router and will connect back to our internal LAN using VPN, the problem is that on the 877 I have to set the VPN config to connect manually, this is because if it is set to auto the 877 will connect back to our VPN concentrator even if the 877 is not currently the active router (this then causes problems with routing from our layer 3 switch in our data center).

The question I am asking is there any way to tell the 877 to only connect the VPN when required - i.e when it becomes the active router.

I am using Ezvpn to do the VPN connection.

Thanks in advance.

Simon

Giuseppe Larosa · ‎12-11-2008

Hello Simon,

if you are using any type of PPPoX on the 877 for the ADSL link you should be able to use the DDR feature called dialer-watch:

it monitors the presence of some routes in the routing table if they are missing it triggers the call.

You need to run a routing protocol on the common lan where you have already configured HSRP.

see the following

http://www.cisco.com/en/US/tech/tk583/tk372/technologies_configuration_example09186a0080094c1f.shtml

Hope to help

Giuseppe

simoncroak · ‎12-11-2008

Hi Giuseppe,

Thanks for your reply, that seams todo what I need! I will look into it more and see if I can get it to work!

Thanks again!

Simon