Windows DNS strange behavior

[cmshowers]

Hello Hardforum,

I have a couple new Dells running XP SP3 with this strange quirk. All the office PCs are set up with a Primary DNS server that is a local Linux box running bind that resolves a couple of local servers. The Secondary DNS is set to one provided by our ISP. These settings are assigned from DHCP.

Every once in a while, these problem machines can't resolve the local machine names. I used wireshark to try to diagnose the problem and all that I learned is that when the local servers aren't being resolved, Windows is never trying the local DNS server; it simple goes straight to the secondary.

I have had the local DNS server running in this configuration for around six months and have never had any trouble resolving local names on any existing boxes (XP, Vista, or Linux). This seems to be something screwy that Dell did to the PCs before shipping. I tried resetting the network stack using the command "netsh int ip reset <logfilename>". This found several interesting issues but my intermittent problem still persists.

Anybody have any clue about this? I know this is a hard one to diagnose without toying with the actual machine so I appreciate any suggestions for diagnostics!

CS

 

[Asgorath]

I'd say just set the client machines to ONLY use your network's DNS. Your network's DNS can then use the ISP's DNS as it's backup. That way your local resources will always be available to look up.

 

[Orinthical]

I'd say just set the client machines to ONLY use your network's DNS. Your network's DNS can then use the ISP's DNS as it's backup. That way your local resources will always be available to look up.

+1

Configure your internal DNS to use your ISP's DNS servers as forwarders.

 

[cmshowers]

Thanks for the suggestions, guys. When I get around to setting up local redundant DNS servers (I've been toying with DNS using LDAP) I will implement this as a fix. But for now I don't trust the local DNS server to not crap out on me

 

[Orinthical]

Thanks for the suggestions, guys. When I get around to setting up local redundant DNS servers (I've been toying with DNS using LDAP) I will implement this as a fix. But for now I don't trust the local DNS server to not crap out on me

There's no way around the behavior as it's been around since Windows implemented DNS support. Once windows finds a DNS server that works it tends to 'stick' to that server until the server stops responding. Even though it's a horrible idea, one way around this would be to use only your ISP DNS servers and create a HOSTS file on each of the workstations to resolve your local servers.

 

[Asgorath]

There's no way around the behavior as it's been around since Windows implemented DNS support. Once windows finds a DNS server that works it tends to 'stick' to that server until the server stops responding. Even though it's a horrible idea, one way around this would be to use only your ISP DNS servers and create a HOSTS file on each of the workstations to resolve your local servers.

:: shudders :::

Just build a DNS server that doesn't go down. And with DNS forwarding to your ISP's (or opendns.org) DNS servers, it should be pretty dang reliable.