DNS Loop

[jonathan]

I've had an issue for a long time, and sort of figured out how to fix it. I just want to know if I did things right.

At one point I started having problems with WinGate installed on a server with two NIC (one for the LAN, the other for WAN through a DSL modem), specifically with the DNS Resolver service. Without apparent reason, it would start making hundreds/thousands of DNS requests per minute, consuming most of the processor time, but moreover, since I was logging both the DNS Service and DNS Resolver service, the logs were filling quite rapidly (one time it even filled the disk up, rendering the server unusable for a noticeable period of time)

I discovered that my LAN NIC's configuration (manually entered) was faulty. It had, as preferred DNS server, the entry "192.168.0.1" (itself). So when not connected to internet a network client making a DNS request would trigger a loop, since WinGate, not being able to reach its preferred DNS servers, would apparently rely on the NIC's configuration and re-issue to itself the request.

I removed the DNS server entry (in Windows' own NIC configuration), and everything seems to be working fine. But I am still concerned. Apparently it would happen even when connected to internet. Is it because the ISP's DNS servers became at some point unreachable and WinGate used "192.168.0.1" as a backup ? If so, then it won't happen anymore. If not, could it happen again ? Is there a concept I'm missing ?

Thanks in advance for any feedback.

[antic_ip8n]

I've had the same problem, so I am trying your solution. Will let you know if I get any further problems. If anyone else has more insights please post.

This may have been the cause of the massive memory usage of wingate and blue screens of death...

Cheers.

[Pascal]

I've had the same problem, so I am trying your solution. Will let you know if I get any further problems. If anyone else has more insights please post. This may have been the cause of the massive memory usage of wingate and blue screens of death...

At any stage when you have inadvertently configured a DNS loop you will see a massive increase in the amount of memory used (Followed usually by the death of the Server)

The problem is that an unanswerable requests gets forwarded to the one DNS server, who, also unable to answer it, forwards it back and so they keep on playing ping-pong until the system runs out of resources.

This is a common scenario where people setup a DNS server as their primary and have WinGate request from that server, but then configure the DNS server to get any unanswered responses from the WinGate server.

Has your problem been resolved by removing the loop, then ?