[VPN] IPSec tunnel with Linksys BEFVP41 not passing traffic

[John Corey]

Hello, I hope someone may be able to cast some light on this problem.

For several months we have had a link between an office in Australia and an office in the UK using a Linksys BEFVP41's with an IPSec tunnel. The link was very much problem free until late last week when it ceased passing traffic. The router shows that the VPN is connected. The VPN logs show connection success though the connection repeats every few seconds. A ping from a host in the UK LAN reaches a host on the Aust LAN and is replied to though the reply does not get back to the UK. (it correctly uses the router as the default gateway) A ping from a host in Australia does not appear on the UK LAN.

I am wondering if the number of hops from one office to the other may be the problem here but have not been able to locate any information that says it might be. A traceroute initiated in the UK reaches the Aust box after 27 hops, however a traceroute iniated in Australia takes over 30 hops. (approx 34) A Window PPTP VPN works OK over the same path being NATted through the Linksys boxes.

Any suggestions at all appreciated.

Regards
John Corey