Published on 2013-06-30
Prerequisites for this article
To read this article you should understand the following concepts:
– VPN
– PPTP
– routing
– network and netmask
– DNS server IP
– configuring PPTP VPN on Windows 7/8
The Problem
Suppose we have a PC with Windows 8 (or Windows 7) and we have administrator privileges on it. Now we decided to connect to our workplace with PPTP (server is already configured on remote site and it’s configuration is not covered by this article).
Once we have configured our VPN connection we can see that there are only 2 options to configure IP networks going to VPN tunnel:
1) Use VPN as a default gateway (all packets go to VPN)
2) Use VPN with only one route to the network, based on peer’s PPTP internal IP address (say if we connected to remote peer with 192.168.15.1 VPN address, we route all 192.168.15.0/24 network there).
What if we want to route more than one specific networks to VPN and everything else to our default internet gateway?
A special software exists to perform this kind of tasks, that is called ‘Connection Manager’ (CM). But this article is not about 3rd party CMs.
All we want is configure custom routes, going to VPN, with native Windows 7/8 tools, which will be automatically enabled once you connect to remote site (and they will be automatically removed, once you bring the VPN connection down, this is a default Windows behavior). Continue reading »