Networking

Fixing DNS and authentication problems when using a VPN

When you use a VPN to access a remote network you might need some configuration changes on the client PC to ensure you can access resources on both networks.

Some of my colleagues use the standard Microsoft VPN client to connect to the network at a subsidiary. I guess one day we may set up a site-to-site connection managed by the two routers, but for now we use individual connections. Here are some tips based on our experience.

DNS - accessing remote resources by name

When I first set the connections up I was given both the IP address and the name of a server on the remote network. I soon discovered that trying to browse to the server by name didn't work so I just provided shortcuts to the IP address.

That was fine for accessing file shares but ran into problems with Outlook 2003, which was trying to connect to the remote Exchange server. Applying one of the standard email troubleshooting steps, I deleted the mail profile and recreated it; Outlook still wouldn't connect. I then edited the profile to turn off cached mode; no joy. I restarted the PC. On restart, Outlook asked for the remote Exchange password but then told me "Your MS Exchange Server is unavailable".

Once again I deleted the profile & started Outlook. Clearly Outlook could connect to the remote Exchange server because it verified the user name correctly. But then it would just repeat that the server was unavailable.

Finally I discovered that I needed an entry in the local "hosts" file on the client PC. To do this, I first started Notepad with Run as Administrator (this was a Windows 7 client and without the "admin" mode you can't save files to the system area).

About

Mark Pimperton BSc PhD has worked for a small UK electronics manufacturer for over 20 years in areas as diverse as engineering, technical sales, publications, and marketing. He's been involved in IT since 1999, when he project-managed implementation ...

Editor's Picks