Routing traffic via IPSec VPN incase primary link goes down

Unanswered Question
Feb 6th, 2009
User Badges:


We are having MPLS as the primary link running BGP & we plan to have IPSec vpn as the standby.We wanted to know how to divert the traffic via IPSec vpn incase of primary link failure.I have attached the network layout.We had thought of IP SLA in the backend L3 switch but the switch doesn't support IP SLA.We cannot upgrade this switch due to some internal company policy & we are exploring any options other than upgrade.

Any ideas ?


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
celiocarreto Fri, 02/06/2009 - 00:41
User Badges:


you can use a routing-protocol between L3 switch and Cisco 2811. In addition a DDR (ip route 10.x.x.x 255.y.y.y Next-Hop-IP 254) in direction of the firewall.

Regards, Celio

sachin_mon Fri, 02/06/2009 - 04:27
User Badges:

Hi Cello,

Thanks for your reply.

When you said routing protocol do you mean dynamic routing protocol in the switch ?

Currently we plans to run BGP in the WAN cloud & static routing in the LAN.Plus, the switch is having IP Base & cannot upgrade it to another IOS.


andrew.andy316 Fri, 02/06/2009 - 12:53
User Badges:


In addition to what Ceilo said, you would have to redistribute the BGP routes into an IGP (RIPv2 given the IP Base image on your switch) routing process.

When the link goes down, the learnt route will be removed from the switch's routing table and the poisoned backup static route will be installed.

Please note however that redistributing BGP into an IGP process is not usually recommended although given the small routing domain you should be fine.


This Discussion