Hi, I have a Cisco 801 router at one end and a PIX 506 at the other. VPN from 800 to PIX is OK However a PC connected to the router will work with no probs for (almost exactly) 15 mins. It will then have to wait for the line on the router to drop, be re-established, and then it will work again! I have a modem dial-up and VPN Client connecting to the same PIX, and every 15 mins (if you are running a "ping inside_host_address -t") you will see it drop one packet and then not drop another for 15 mins!! Isakmp lifetime is set to 86000 on the PIX so it won't be that - NAT timeout is set to 3 hours.
Any ideas?