DNS Setup Help

[GeorgeTuk]

Hi guys,

I think I have confused myself but my Domain Controller no longer accesses the internet but this has meant that parts of Exchange 2007 OWA aren't working.

Can anyone suggest the settings? Should the first DNS server of the DC be external?

Thanks

 

[TeflonJim]

No, it shouldn't be external, it'll just break things for an AD domain.

Check your Forwarders if you have any set?

To check the forwarders:

1. Open the DNS Console
2. Right click on your server and select Properties
3. Select the Forwarders tab
4. For each IP listed there (if any) run:

nslookup

http://www.google.com

IPAddress

e.g.

nslookup

http://www.google.com

4.2.2.4

That will check to see if the name servers you're using are responding. If they are not, remove them then try:

nslookup

http://www.google.com

You may need to flush your server cache first. That can be done from the DNS server console by right clicking on the server and selecting Clear Cache.

By default your server will use Root Hints (see Root Hints tab), which is more effort than Forwarders but should work. If it does not, you need to check network access to see if your server is allowed to send outbound UDP on port 53.

If it does work with Root Hints, but not with your forwarders you have a few choices:

1. Raise the issue with the forwarder host (your ISP?)
2. Find new forwarders
3. Continue using Root Hints

HTH

Chris

 

[GeorgeTuk]

There are no forwarders set so I guess is the issue. Because I did mostly secure internal networks before this is a bit new for me.

So for forwarders could I use my ISPs server DNS? Its 195.216.16.65 and they are called Star.

Thanks

 

[TeflonJim]

Yep, those would do. I would have to suspect a network issue if it's failing to resolve with root hints (normally just too much blocked).

Anyway, if you set the Forwarders to your ISPs DNS servers, then try again?

Chris

 

[GeorgeTuk]

I think your right there TeflonJim, since it is actually on a hosted server locked down to currently only allow Port 80 and 443 traffic.

What ports should I be looking to unlock to get the DNS through?

 

[TeflonJim]

UDP Port 53 (outbound only). If you're using Forwarders, only to the Forwarders, if you're using Root Hints, to everywhere.

Chris

 

[technome]

two cents...
If you use forwarders, use two to your ISP's DNS servers and a couple to other ISP's servers..more then once I had the providing ISP change/break their DNS servers for a period of time.


........................................
Chernobyl disaster..a must see pictorial

http://www.kiddofspeed.com/default.htm

 

[drummelhart]

Open DNS
right-click the name of your DC on the forwarders tab should be the IP addresses of the ISP's DNS Servers. Try that and then see if you can reach

http://www http