I have a Watchguard X1000 and a Cisco 1800 Series T-1 Router in production.
There have been intermittent issues with VPN connectivity to the Watchguard Firebox.
E0/1 on the cisco is connected to the External interface on the firebox.
I have used simple ping tests to narrow down where the issue may be.
I started from the outside in and here is what I ended up determining.
When I put a heavy load of datagram pings from the router to the firewalls external interface, I get alot of time outs. I'm talking a heavy load of 20,000 pings at 5,000 datagram size per. Both interfaces are set to auto negotiate full duplex and I was wondering if I shouldn't just hard code these two interfaces.
I'm pretty sure that the problem with my disconnecting VPN's is between these two devices from the testing that I've done so far.
Any suggestions or advise would be greatly apprecited.