Cisco VPN Software and Local Network conflicts

This is a post for anyone else having connectivity issues with their LAN while connected to a VPN of some sort. When setting up the Virtual Private Network (VPN) on our new server we encountered a number of issues of not being able to connect to the local network while the VPN was established. Initially it was merely an inconvenience and something that we could live with, but as time went on we needed to stay connected and access files from the local network, it grew more and more irritating.

After much searching on the internet for a solution with terms like “Cisco VPN Local Area Connection Issues”, “Cisco VPN LAN Issues”, “Cisco VPN LAN files” and various inflections of we didn’t find anything useful.

While trying to sort the issue, I noticed that the VPN was establishing itself on the subnet of 192.168.1.x, that in itself is not a problem but we were running our LAN under the same subnet. It was only then that we realised that we had a conflict as the VPN was overriding the local subnet so on trying to access 192.168.1.5 it would attempt to contact the remote server group (which didn’t exist).

If you’ve got the same issue, the fix is simple, all you need to do is change your local subnet to something else i.e. 3, this means when the VPN is connected it will connect over 1 and the LAN will remain unaffected –lovely!