DNS and dynamic IP. Is this possible?

[Guest]

My installation is the following. ADSL Broadband router (w/NAT) getting dynamic IP addresses from ISP and delivering Internet traffic on our local network PCs. On our Domain Controller there is a DNS and a DHCP that serve local PCs. Every DNS query is served by our local DNS, on wich I have enabled forwarders. Both local and Internet queries are served, but after a period of time (that is not clarified) the Internet queries are not served. It is required to reboot the machine in order to have the DNS serving the Internet queries again. A restart of the service itselfs doesn't do anything

Is it possible to have the DNS keep working for both local and Internet queries on a dynamic IP

Nikolas Demiridi

 

[William Stacey [MVP]]

Is it possible to have the DNS keep working for both local and Internet

queries on a dynamic IP?

Not sure that is the issue here. Your ISP dns ips should be fixed, so it
should not matter if the dynamic IP on the router changes. Make sure:
1) All clients and servers point to the local dns server IP only. Not the
isp too.
2) On the DNS server, forward to the ISP. Turn off recursion in the forward
tab for testing (turn on later if you like.)
3) Clear the cache on the dns server. Do IPconfig /flushdns on the dns
server and client.
4) Do you get the same thing?

If so,. you need to start NetMon on the DNS server to see what is happening
with the dns queries - both inbound and how/if it is forwarding them. HTH

 

[Nikolas Demiridis]

Thanks for taking the time.

1. All clients are DHCP enabled, meaning that all clients get the local DNS
only. The only server (domain controller, DHCP, SQL, IIS, DNS) is configured
correcty (specific IP, DNS itself)

2. I actually forward to 4 different ISPs. (Recursion ON)

3. I always clear cache

4. Same thing happens

Can you please advise on how to use NetMon in order to see what happens?

Thanks a lot

Nikolas Demridis