Can you create a VPN tunnel with DDR and the aux port?

[jeffrey.lawson]

I have 4 sites connected to the internet via DSL and interconnected via VPN. I love the setup and how it works but I wanted to add some sort of redundancy...Could I hang a 56k modem off of the aux port that dials into the internet (a provider that gives static IP's and allows VPN traffic) and use Dial on Demand Routing if the DSL link went down? Could I create a VPN tunnel from the aux port to the main site once the connection was established? Then could it periodically check to see if the main link was back up and switch back if it was?

[wdrootz]

I think this might help you out: http://www.cisco.com/warp/public/cc/so/neso/vpn/vpne/vpne_an.htm

[jeffrey.lawson]

Thank you for the link, it was very helpful for part of my question. The only thing it does not answer is if I can use these tunnels with DDR and dial into the internet to establish a new connection when the main tunnel goes down. Has anyone else used the aux port with a modem to connect to the internet and establish a tunnel when the main link goes down. That is the most redundancy I can afford.