SLA Monitoring on Cisco Router for achieving failover to Backup Internet link

[sreeraj.murali]

Hi,

Can anyone help, if i can use the SLA Monitoring feature to achieve failover to Backup Internet link on Cisco Router. Please provide with Cisco documentation with regards to same.

I want to achieve High Availability for my GRE Tunnel to US from Bangalore.

Thanks

Sreeraj

[Georg Pauwen]

Hello Sreeraj,

a fairly simple EEM script could achieve this. It depends on your setup: are both connections terminated on the same router, or two different routers ? Can you post the configs of the device(s) ?

[Junaid Shah]

Per my understanding you are mentioning two things here that are failover to backup internet link & HA for GRE Tunnel.

For failover to backup internet link using IP SLA, see below link or you can search using google and you will find good documentation for it

https://supportforums.cisco.com/document/30296/using-ipsla-change-routing

For GRE it's tricky because in GRE tunnels you specify source interface but you can achieve that using dynamic routing protocol like EIGRP and then bring both tunnels up at the same time but make the secondary one worse by changing its metrics like delay etc so the second tunnel will start passing traffic only when the first one will go down.

https://supportforums.cisco.com/discussion/11256461/gre-tunnels-failover-sla

Hopefully that helps.