I've set up a VPN connection as described in this question: Set up VPN Server on Windows 7 that shares internet connection
My VPN server is behind a router, and local addresses are all 192.168.1.x. When I connect to the VPN from within my local subnet, I am still able to access the internet through the gateway at 192.168.1.1. When I connect with a client from outside of my subnet (e.g. with a laptop at a secondary location), I can't access the internet as long as the VPN is active. The problem appears to be the fact that I can't access the VPN server's local gateway at 192.168.1.1 (i.e. the router) when I'm connecting from a client that is outside of the VPN server's subnet. When I disable using the default gateway provided by the VPN, I'm able to access the internet but of course this goes through whatever gateway I was using before and thus my internet traffic doesn't actually go through the VPN.
I'm not sure how best to troubleshoot this problem, or what other information is required. Please let me know if I'm missing anything or what I need to change so that I can access the internet from outside my subnet, and have all of my traffic routed through the VPN.