We have a dedicated server that is primarily used to host our website. I've been tasked with determining the feasibility of setting up a VPN connection from it to our Internal Network at our offices for a few ease of use purposes. My concern is that if I establish this VPN connection our Website will only be available internally and not to the internet in general. I'm concerned about this because in everything I read the fact is stated that by default all network traffic is routed over the VPN connection when it's established, is this also true for applications such as IIS that are listening for incoming connections?

TL;DR Will having a VPN Client up and running cause a problem with server applications that may be listening on the NIC connected to the Internet due to changes that VPN makes in the routing tables?