Question : DNS problems with Server 2003 DNS server and Linksys VPN

I have two offices next door to each other, both with their own DSL connections. Both sites have Linksys VPN routers and there is a tunnel set up between them. At site A, there is a Windows 2003 server acting as a Domain controller, DNS server, and file server. Site B has an XP box with a share set up for users at site B. The reasons for the VPN are:

1. Both sites WERE using the same DSL connection, servers, LAN, Domain, etc. and since each user at site B is already set up on their individual machines under that domain, I needed a way to access the Domain server to log a user into a new machine if they changed computers.

2. The server at site A does the backup for both locations. I have a program to sync Site B's shared files to the server at Site A. (Not talking about much data, maybe 10MB changed per day).

Everything else used to work great even if the VPN was disconnected. I only had to have it connected to add a user to a new machine at site B or to transfer files from file server at B to server at A.

Now the VPN keeps going down (2 - 3 times a day) and when it does, the users at site B cannot connect to the file server at site B. They each have a drive mapped to that server using UNC path. They are also unable to ping by UNC, but can by IP. Each user has static DNS set, primary is DNS server at site A, secondary is ISP's. This is how it has always been and it has always worked whether the VPN tunel was up or down. All of a sudden, it does not work.

I have tried to set the static IP to obtain automatically - no change when VPN is down.
I also included the servers IP and name in users HOST file - no change.

Any ideas?

Answer : DNS problems with Server 2003 DNS server and Linksys VPN

I'm not sure how this was originally working if the VPN was down, but the way it's configured now won't give you internal DNS resolution if it can't get to the DNS server at site A.  The reason for this is, the DNS server at site A will answer internal queries and then look to the root servers if it can't resolve from the internal records.  However if the VPN is down, since the secondary DNS server at site B is your ISP's server, you won't get DNS resolution for your internal network since your ISP doesn't have this info.

Have you tried setting your secondary DNS server at site B to your Linksys device?  This is typically the best thing to do if you don't have a full DNS server at that location.  The reason being, that your Linksys device will typically do the DNS resolution on your internal network, then automatically check the ISP's DNS servers if it can't resolve it.  This way, you'll get internal and external DNS resolution if the VPN is down.  That should fix your issue.