I have two Remote offices both with dual static ISP connections (Cable & DSL). I need to setup an IP Sec gateway to gateway VPN with auto failover. I also need to setup two dialup modems that are always nailed up. One side being a ppp client and the other side being the ppp server.
I need the dial-up ppp interface to route a narrow range of traffic while the VPN is failing over or if service fails on both WAN interfaces. I don’t want to route all traffic over the PPP interface, only traffic on TCP ports 5000 to 5100.
I have configured this setup with two different commercially avaible brands of VPN routers that support failover. The main problem with them is that the VPN is down for too long during failover and restore, typically between 30 seconds and 3 minutes. My application is such that I need a narrowband of traffic to be constantly passed. Nailing up dial-up modems is plenty of bandwidth and a local telephone call. I want to acheive a maximum delay time of 5 seconds before the PPP adapter’s route kicks in.