DC DNS Errors and blocks internet traffic

Well I have one more assumption, which is this: your client computers are only getting the DC's IP address for DNS queries.  So the DC is operating as a caching proxy.  And when the DC gets requests for external sites, it doesn't know what to do with them.  So: leave DHCP alone, but in the DNS settings for the DC, make the first entry the IP address of your router.  That well the DC will authoritatively answer queries in relation to computers within AD and pass on everything else.  Try it.

OK so change the DNS setting on the DC from:

.10 (Itself)
.11 (Non-existing DC) LOL

To:

.1 (The router, to provide routing for external request)
.10 (To itself for DNS request as well)

Am I understanding correctly? Becuase it does sound the probable solution.

And the alternative DNS server could be your Internet provider.

You could also use <a href="http://www.opendns.com/solutions/overview/>openDNS[/url]

OK, so I have made plans to be here tomorrow night to implement these changes. Also I am now very intrigue by OpenDNS and will be looking into that closer.

I will update on my status either Monday or Tuesday.

Thanks

Yes, please update us.
Good luck!

Good call Jerry.  My preference would be (from the DC) to query the router rather than the ISP, for various reasons (local caching, lower maintenance) but the OpenDNS project is always worth a look.

And yes Chris, I would do the change you suggested.  If you wish to implement OpenDNS, I would do it at the router, not at the DC.  DNS is very noisy traffic with latency issues and it's best to keep as much of it local as possible.

I think you're right Rob. Just as what Chris stated that he has only one network connection

I set it to:
.10.1 (Router)
.10.10 (Self)

It appeared to be working this way and then about 15 minutes ago it happened again, the internet went completely down. So I set it to opbtain its own info and then reentered the IP info and that brought the internet back up.

 

Right, so you're now (potentially) entering the realms of flaky network cards or faulty software or something of that ilk.  For further diagnoistics, when the internet appears to be down, from a client machine in a command prompt run the command "nslookup www.google.com".  What happens?  Repeat from the DC.

What network switch do you have between the DC and the other PCs/devices?  What speeds/duplex are the cards running at?

I will pull one next time the internet goes down as well.

Code: [Select]

C:\Documents and Settings\cwilcox>nslookup www.google.com
Server:  dc01.ptc.local
Address:  192.168.10.10

Non-authoritative answer:
Name:    www.l.google.com
Addresses:  74.125.47.105, 74.125.47.103, 74.125.47.106, 74.125.47.104
          74.125.47.99, 74.125.47.147
Aliases:  www.google.comAs for the switches the DC connects to an AOpen 10/100 and I also have an Airlink 10/100/1000 on the system as well. Both 24 port.

Have you tried setting your ISP's address to be an alternate DNS server?

I have not tried that yet. I will try that this weekend or next time it goes down. I went out and got a network card and some memory for the DC, so I am going to try and get all that in this weekend.

So it went back down again. I implemented my ISPs IP and that did nothing. I tried promoting another DC that I made a few days ago and it couldnt bring back the internet either. So this time I tried something a little out of the norm for me. I turned off all the lights and went home! Came back up this morning and the &*^% fixed itself. So I am going to get the memory and the network card installed this weekend and see if that helps. If you guys have anymore thoughts I am still listening and still very thankful for all. This stupid internet is driving me crazy.

Yeah, figures...

Just one thing - I think I got things in the wrong order before.  The DC should query itself first for DNS, since it is authoritative for all local matters.  Instead of:

I set it to:
.10.1 (Router)
.10.10 (Self)

The order should be:

DNS1: x.x.10.10
DNS2: x.x.10.1

Sorry for the confusion!

OK, I will fix that immediately. It went down this morning again. I also have the memory and a new network card to throw on it. I alsow changed out the patch cable and moved it to my other switch.