Solution was to force all traffic over VPN. My VPN client gui had this a simple check box - though there are script commands that can do it as well. =============================================================== I am running Open VPN on three devices over Netgear DG834GV4 ( have also tried this on a Sagem 2504). Computer A (Windows 7, Viscosity VPN client, ethernet) runs fine, no problems using VPN. Computer B (Windows 7, Viscosity VPN client, Linksys wireless adapter)runs fine for about ten minutes or so, then all websites fail. VPN is still connected(in a connected state) and internal network is ok. Computer C (Android, Open VPN for Android client, ethernet) device runs fine, no problems using VPN. I have tried using default blank DNS in IPV4 config, Open DNS servers via the IPV4 configuration, DNS via the VPN itself or completely no DNS at all. My VPN provider has tried to assist but the only responses I've had are : A) Your router must not work with multiple devices and VPN. B) Try different ports. A) is obviously not true B) I am doing this next, but what alternative ports can I use for a VPN? When I disable the VPN connection on Computer B, it works indefinitely, which says to me it's clearly an issue with the VPN connection. The settings for the VPN are identical to Computer A. I found a person having a very similar issue, however no replies to that thread: "On one of my home PCs (Windows 7 Professional 64BIT, wired connection) I have problem with VPN - after 2-5 minutes after connection to my workplace it "freezes" - i.e. pings stop reaching my work computers, but connection itself reports "connected" state. If I disconnect/reconnect it manually everything returns back to life - for several minutes. I have 3 more different computers on the same network (2 laptops, one workstation), some of them are wired, some wireless, one even has the same OS )Windows 7/64bit. All have VPN configured the same way to the same workplace - but they work perfectly without disconnections/freezes, and the forth PC - does not." I read elsewhere that Windows firewall might be blocking replies from the dhcp server whilst the VPN connection is open. This causes the VPN connection to drop out at the end of the dhcp lease period ...?