DNS server setup problem?

[b4mule]

Im not sure if this is a win 2000 dns server setup problem but...

We run a LAN that has never been connected to the outside world, now we want to put a e-mail server inbetween the lan and the internet. We have used Red Hat linux and set it so it checks the internal DNS server as primary then the ISP dns as secondary. In this configuration it seems to try the primary and then give up, is this a problem with our dns setup.

We have tried setting up so the ISP DNS is primary and the internal DNS as secondary, it seems to work ok but painfully slow as for any internal DNS stuff it is checking the isp DNS first.

Any suggestions?

 

[Provogeek]

Some things to check and try:

How do you distribute IP addresses? Static or dynamic? Are both DNS servers in the settings? (if so, confusion is understandable, it should roll down).

Make sure you DNS server is not setup to be the PRIMARY DNS server for your domain name. If your domain name is xyz.com, do not make your server the primary; make it a secondary (life is easier when you let the ISP or domain host handle the primary DNS). To make an internal domain use something like corp.xyz.com and make your server the primary of that.

Provide your client with only your internal DNS server and have your DNS forward unknown look-ups to the ISP DNS. This give you much better control over your clients ability to do DNS lookups (another way to block stuff from dolts). Your firewall will only need to have port 53 open for this to work (both ways).

The slowness is due to either your Internet link speed or your ISP uses crappy servers. Use some type of caching device (just had a demo Volera my self, nice product). It will speed both DNS lookups and Web Access by utilizing a cache store for frequently visited web pages.