W2K DNS Problem -- 5504 Errors with MX Records, Part II

[Chris Johnsen]

The other post was getting ugly, so I decided to start a new one.

Summary:

- W2K Server connected to a Dell TrueMobile 1180 router which is in turn
connected to a Comcast cable modem.
- Standard DNS records resolve just fine. MX records give me a 5504
error on any domain but my own.

So Far:

- Setting nslookup to use Comcast's DNS server gives timeouts.
- Setting my router as a DNS forwarder gives "Can't find <domain>: Server
failed"
- Setting ISP's DNS as DNS forwarder gives "Can't find <domain>: Server
failed" 99% of the time
- Connecting server directly to cable modem and using Comcast's DNS
servers, every MX query returns the same data.

Weird stuff:

- Setting my DNS forwarder to my ISP's DNS and using my own DNS for
resolution worked for a brief period of time, and only at one point. I
reset the router & rebooted the computer to make sure whatever happened was
going to be persistent, and it was not. There were a few new events in the
event log right before the DNS lookup started working, but like an idiot I
cleared the event log before reboot so I could see what was going on, and no
I didn't save the log first. The messages had something to do with
registering the server in the DNS record.

- I have two XP machines on the router, both using the router's IP as
their DNS servers. nslookup succeeds on those machines (for regular and MX
records), so I strongly suspect this is related to W2K (or more accurately,
my config) and not the router or ISP's DNS servers.

Thanks, everyone!

 

[Michael Johnston [MSFT]]

Chris,
Install Network Monitor or some other network sniffer on the DNS server. Start a trace. Open a command prompt and ping your ISP's DNS servers. If you get
timeouts, you don't have connectivity to your ISP's DNS. If you get replies, type "nslookup" press enter. Type "server IP" where IP is your ISP's DNS. Type
"set type=mx" and press enter. Type "microsoft.com." and press enter. Ensure that you include the trailing "." at the end of the domain name query. Stop the
trace and post it here.

One other thought. It may be that your ISP has set this up on purpose to keep you from running a mail server on their network. They may do this in an effort to
prevent spammers. Just a thought.

Thank you,
Mike Johnston
Microsoft Network Support


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[Chris Johnsen]

Michael,

Thanks for the network monitor idea. I'll try that and post the results.

I'm hesitant to blame my ISP, because I can look up mx records fine from my
XP machines.

-Chris

Chris,
Install Network Monitor or some other network sniffer on the DNS server.

Start a trace. Open a command prompt and ping your ISP's DNS servers. If
you get

timeouts, you don't have connectivity to your ISP's DNS. If you get

replies, type "nslookup" press enter. Type "server IP" where IP is your
ISP's DNS. Type

"set type=mx" and press enter. Type "microsoft.com." and press enter.

Ensure that you include the trailing "." at the end of the domain name
query. Stop the

trace and post it here.

One other thought. It may be that your ISP has set this up on purpose to

keep you from running a mail server on their network. They may do this in
an effort to

prevent spammers. Just a thought.

Thank you,
Mike Johnston
Microsoft Network Support

rights. Use of included script samples are subject to the terms specified at

http://www.microsoft.com/info/cpyright.htm

Note: For the benefit of the community-at-large, all responses to this

message are best directed to the newsgroup/thread from which they
originated.