DNS Issues & Possible DHCP Issues.

[sgscit]

Folks,

We have an issue where the IP address for some reason stops working. It is pretty selective in how it stops working as we can still access most resources.
The resources that are affected are SQL server and the Internet. If we do an ipconfig /renew, we can continue, though sometimes we have to do a number of them or even a full reboot to get access to the resource.

On top of this, to even access the Internet we have to have the DNS server of our Internet provider as the first DNS server. (we have blocked the port to the dns server in the firewall and the number of hits it is getting is phenomenal!)

Back in NT server days we had a forwarder set up so that if we needed to access the internet, the DNS server cached the network address and then forwarded the Internet request to the appropriate DNS server. I have been unable to work out how to do this on 2000 Server.
How do I set up the cache? I don't want to set up a caching server, I just want to add a cache, which in NT was just another zone (or it looked like one)

Any help would be much appreciated.

 

[LedZepRock]

Hi

Forwarders

Open DNS, Right Click over your Zone, Select Properties, Select the Second Tab. Plonk your external DNS IP's in there.

Hope that works for you..

Ta, Simon

 

[GlenJohnson]

Does your internet service provider change your ip's on you? Mine does, via dhcp, it only allows me the address for a few days. There software doesn't always work, so I created a batch file. Whenever I can't access the inernet, the batch file is a simple, Ipconfig /release Ipconfig /renew, and in seconds I'm on the internet. I shouldn't have to do this, but since there software doesn't always work, and I don't want to spend hours on the phone trying to fix something I can fix with a batch file, I just run it. This is just an FYI. Glen A. Johnson
Johnson Computer Consulting
MCP W2K
glen@johnsoncomputers.us



"Defer no time, delays have dangerous ends."
William Shakespeare (1564-1616); English dramatist, poet.

 

[sgscit]

Thanks for responding guys.

I do have a dhcp connection to our DSL router but we are having to refresh the dhcp 2 to 10 times a day on the local machines only, not on the router.

As for Simon's suggestion above, the checkbox to allow forwarders and the root hints area are greyed out.

I've since built a pc with 2000s on it, installed DNS, and attempted to use the forwarders. On the PC with 2000s on it I can browse etc but not on the other machines on the network. If this post goes in I'll be amazed as it will be the only site I can get to.


help??

Pete

 

[e2002]

What is the range of your DHCP addresses. Are there enough available for the number of devices (computers) requesting?

Eric.

 

[GlenJohnson]

When you have problems, what does IPCONFIG /ALL show? Glen A. Johnson
Johnson Computer Consulting
MCP W2K
glen@johnsoncomputers.us



"Defer no time, delays have dangerous ends."
William Shakespeare (1564-1616); English dramatist, poet.

 

[sgscit]

Eric - we have 35% utilisation.
Glen - ipconfig /all does not change whether I do a /release /renew or an /all.

OK - I've done some tinkering and did pick up one discrepency. Our old server had been rebooted on friday and it was serving DNS and DHCP. This has been disabled in services.

But the issues still occur.

I have managed to get the forwarders working on the 2000S PC and now no longer have the external DNS server as the first in the list, in fact it is no longer in the list.
This should releave a few hits on the firewall, though I haven't asked all and sundry to reboot yet.

I'm going to test on a few machines in my area and see if they no longer are affected.

Thanks

Pete

 

[sgscit]

Well I have left the machines running and guess what?....still probs with DHCP. DNS is now ok (or appears to be) and we no longer have the external DNS address in our DNS list - we are now using a forwarder.

But the problem with the DHCP is still alive and kicking.
If I display the ipconfig/all , it comes up as it should.
When we are having the problem where we lose connectivity to the Web, ipconfig/all stays the same. I do an ipconfig/renew and the addresses and details when compared to /all previously nothing has changed.

I have also been advised that this issue also prevents access to network shares.

A temporary fix we have been using for about the last two weeks is to create a simple batch file containing ipconfig/renew. This is then put on the quick launch bar for when the users are affected.

Cheers,

Pete

 

[e2002]

When your computer is having problems, can you ping the ip address of another system on your network and can you ping the ip address of an internet page (198.133.219.25 cisco.com). Try pinging

http://www.cisco.com

as well to check your name resolution.

What protocals are running on your workstations. Is it just tcp/ip?

Eric.