RE: [IMail Forum] OT: Alternate DNS server issues

[Kevin Bilbee]

Title: OT: Alternate DNS server issues

You probably have a default route issue at each site. We have the same setup.

 

The all sites frame relay routers need to know what to do with an unknown packet, like forward it to the internet router by setting up a default route. At the moment their internet connections probably are not being used.

 

Example:

Frame relay router is the default route for all computers. The frame relay router has a default route defined as

 

ip route 0.0.0.0 0.0.0.0 10.5.12.253

This causes any packets destined to an unknown network to go to the 10.5.12.253 internet router.

 

Also to make this work the frame relay router needs to either have rip or equivelent running or all known networks need to be explicitly defined in the routing tables of the frame relay router.

 

 

Kevin Bilbee

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of Sharyn Schmidt
Sent: Thursday, April 06, 2006 8:18 AM
To: Imail_Forum@list.ipswitch.com
Subject: [IMail Forum] OT: Alternate DNS server issues

Hi,

I need to pick the brains of the experts on this list.

Here is my situation:

I have my main site here and several remote sites. The remote sites are connected to my main site here via frame relay. My internal DNS server that hosts my AD domain is located here, as well as my primary nameserver that is authoritative for my own domain and acts as the forwarder for my internal DNS server.

My main site, and all my remote sites have their own internet access. In DHCP for all sites and in the NIC configurations of all the servers I have my internal DNS server configured as the primary DNS server and then I have the respective ISP's dns servers as the alternate.

Today, internet access at my main site dropped. Theoretically, this shouldn’t have affected the other sites, but it did. No one was able to browse. My WAN line was fine. I RDP'd to the server (running win2k) at 2 of my sites and was able to access the internet with no problems, using the configuration as stated above.

None of the workstations (running XP pro) at either of those sites was able to browse the internet, even though the DNS server settings in DHCP were IDENTICAL to the DNS server settings configured in the NIC of the server.

In the other 2 sites, this configuration didn’t work at all.

Here are my questions:

What triggers a machine, either server or workstation to give up trying to use the primary dns server and hit the alternate? Did this behaviour change from win2k to XP?

On my win2k server, even though it could contact the primary DNS server, it couldn't get an answer so it went to the alternate. My workstations just gave up.

Is there a way to change this behaviour?

I understand that I can set up local internal DNS servers at each site with a dynamic DNS zone for my internal domain and then forward to the ISP's DNS server for external but I was really trying to avoid that.

Thanks,
Sharyn