VPN as backup for a leased line

[jimmyjoseph]

Hi,

I have a T1 leased line to a partner location. The leased line is terminated on a router outside my firewall. Now as a backup ican i configure an IPsec VPN to the same partner site and have a floating static route so that traffic gets routed via the IPsec VPN in case the T1 link fails.

Is there any potential bottleneck in doing this? Please advice.

regards,

jimmy.

[vcjones]

If the VPN is provided by an external devices, such as a firewall or another router, there is no problem doing this. However, if the VPN is implemented on the same router as the path through the leased line, I found that the access list used to define the VPN also tried to VPNize the leased line, which was not desired. Maybe someone else can point out a way around this restriction?

In the meantime, you may find the points brought out in the redundant VPN whitepaper on my web site useful, even though what you are trying to do is slightly different, and consequently the specific examples given can't be used directly.

Good luck and have fun!

Vincent C Jones

www.networkingunlimited.com

[jimmyjoseph]

Hi,

Thanks for your response. If I statically route the remote branch traffic to a GRE tunnel Tunnel with a higher administrative distance call the crypto map at this tunnel then will i overcome the bottleneck mentioned by you?

regards,

jimmy.

[n-meadows]

The basic idea is OK the problems might come in the detail, the best method I have used is the same floatinf static routes but use ipsec through GRE tunnels then you can point the routes for the VPN'd networks into the tunnel i.e.

'ip route x.x.x.x mask int tunel (number of tunnel int.) if you have configured your crypto maps correctly (a hair pulling process) the theory is that the traffic you point down the tunnel is VPN'd and the T1 traffic is not, this is assuming you are wanting this on the same router.

[jimmyjoseph]

ok..thanks..I will try it out.

regards,

jimmy