Resolving DNS

[beer]

On an internal network, a particular domain controller resolves to its internal address. I.E, if I ping xyz.thiscompany.com, it resolves to a local address. Normally, when you are on the public Internet, you can ping xyz.thiscompany.com and resolve it to the external address. However, one computer in the internal network resolves it to the EXTERNAL address! It is baffling and I have no where where to look. All computers on the network are DHCP-ed from the same firewall; they are logged onto the exact same domain controller; they have the exact same hosts file. Where do I look?

 

[skyking]

Are there entries in the hosts file that direct you to the site, or do you rely on internal DNS(as you should, if possible)??
If not, then that machine has the external DNS server(ISP's) in the TCP/IP protocols. Don't ask me how, but I bet it does not have the DC listed for DNS.

 

[beer]

we are relying on internal DNSs

The computer fetches all the DNS servers, etc, via DHCP, from the same firewall as everyone else, but only it has problems How could that be possible?

 

[bsobel]

Originally posted by: Elemental007
we are relying on internal DNSs

The computer fetches all the DNS servers, etc, via DHCP, from the same firewall as everyone else, but only it has problems How could that be possible?

As Skyking said, you sure it's not in the host file?
Bill

 

[kt]

Was the machine at one point using an external DNS? Maybe you need to purge the DNS cache? Or you can try forcing the computer to re-register DNS names.

 

[beer]

Originally posted by: kt
Was the machine at one point using an external DNS? Maybe you need to purge the DNS cache? Or you can try forcing the computer to re-register DNS names.

that makes more sense than anything. I'll try it tomorrow.

I am 100% the hosts file is not involved in this. It is the exact same as every other hosts file. Unless there is a file other than 'hosts' in c:\windows\system32\drivers\etc that i'm not aware of.

 

[skyking]

Originally posted by: kt
Was the machine at one point using an external DNS? Maybe you need to purge the DNS cache? Or you can try forcing the computer to re-register DNS names.

If it gives you any more trouble, give it a fixed IP and point it to the dns servers manually. That is worth a try, and I prefer hard IP's on networks anyway, if it is not too much trouble.

 

[beer]

Originally posted by: skyking

Originally posted by: kt
Was the machine at one point using an external DNS? Maybe you need to purge the DNS cache? Or you can try forcing the computer to re-register DNS names.

If it gives you any more trouble, give it a fixed IP and point it to the dns servers manually. That is worth a try, and I prefer hard IP's on networks anyway, if it is not too much trouble.

We just finished getting rid of hard IP addresses. It was a NIGHTMARE. People (attorneys, auditors, etc) had to come by and ask us how to get their laptops working. We'd always have to 'find' a new address before we could use it, and I couldn't tell you how many times we had IP address conflicts that took an hour to solve.

Good riddence to IP addresses. They're 'cool', if you say so...but try dealing with 200 computers with hardcoded addresses.

 

[skyking]

I qualified that with "not too much trouble"
That is way too much trouble, LOL! I do it on smaller networks, and still leave DHCP going. I just hard set the IP's outside of the DHCP range, therefore never a conflict. With 200 boxes and maybe only 1 gateway, you do not have much room outside the DHCP range!

 

[beer]

Originally posted by: skyking
I qualified that with "not too much trouble"
That is way too much trouble, LOL! I do it on smaller networks, and still leave DHCP going. I just hard set the IP's outside of the DHCP range, therefore never a conflict. With 200 boxes and maybe only 1 gateway, you do not have much room outside the DHCP range!

Our IT department tends to be conservative. We just ditched token ring four years ago (16 mb/s); we still use an AS/400 for most of our realty management and accounting (awesome platform...so stable), we just got our first hardware firewall and we ripped out hubs and put it switched last month

 

[Nothinman]

Christ I setup DHCP and DDNS on my internal home network with only a handfull of nodes because I got tired of updating DNS whenever I plugged in a new machine, now it boots up, gets an address and everything works without me doing anything. It also sucked changing IP info when I moved my laptop between work and my network.