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Error when primary DNS in spamfilter is down

Printed From: LogSat Software
Category: Spam Filter ISP
Forum Name: Spam Filter ISP Support
Forum Description: General support for Spam Filter ISP
URL: https://www.logsat.com/spamfilter/forums/forum_posts.asp?TID=5021
Printed Date: 04 November 2025 at 2:53pm


Topic: Error when primary DNS in spamfilter is down
Posted By: sirrar
Subject: Error when primary DNS in spamfilter is down
Date Posted: 25 January 2005 at 5:47am

Hi

I've found out to define a secondary DNS server in spamfilter.

Problems is, when it should use the secondary server (when primary is down) I get a socket error instead of lookups.

This results in than all domains has invalid MX records and therefore are rejected.

Im running Spamfilter 2.1.2.402 Registered on a Windows 2003 server, any ideas?

The primary DNS server is a Windows 2003 DNS server located at same machine as spamfilter.

This is a output from the logfiles, when primary server is down.

My server are able to lookup adresses from the secondary server.

01-17-05 08:16:03:923 -- (1724) Connection from: xxx.xxx.xxx.xxx  -  Originating country : United States
01-17-05 08:16:05:375 -- (1724) Resolving xxx.xxx.xxx.xxx - Error occurred during DNS lookup: Socket Error # 10054 Connection reset by peer.
01-17-05 08:16:05:375 -- (1724) - Invalid MX record -
01-17-05 08:16:05:375 -- (1724) xxx.xxx.xxx.xxx - Mail from: mailto:dsa@dsa.xx" CLASS="ASPForums" TITLE="WARNING: URL created by poster. - dsa@dsa.xx To: mailto:dsadsa@todomain.xx" CLASS="ASPForums" TITLE="WARNING: URL created by poster. - dsadsa@todomain.xx will be rejected
01-17-05 08:16:06:467 -- (1724) EMail from mailto:dsa@dsa.xx" CLASS="ASPForums" TITLE="WARNING: URL created by poster. - dsa@dsa.xx to mailto:dsadsa@todomain.xx" CLASS="ASPForums" TITLE="WARNING: URL created by poster. - dsadsa@todomain.xx was received and quarantined. Size: 1 KB, 1024 bytes
01-17-05 08:16:06:507 -- (7732) Time to add Msg to Bayes corpus:9
01-17-05 08:16:06:717 -- (1724) Disconnect

Best regards...

Torsten Christiansen


Replies:
Posted By: sirrar
Date Posted: 25 January 2005 at 6:11am

Hi again

 

Made some debugging.

Tried to put in an invalid primary server. Then spamfilter does as it should do. Says the server is down and will rotate to next DNS.

When my normal prim DNS is primary DNS in spamfilter is stopped (DNS server service is stopped) it gives me the socket error i wrote about in the last mail.

So I think the problem is that Spamfilter has problems recognizing DNS server down when used against at Windows 2003 DNS server??

Any ideas?

 

Best regards...

Torsten Christiansen

Posted By: LogSat
Date Posted: 26 January 2005 at 8:40pm
Torsten,

Can you please check to see if when you stpo the DNS service in Windows 2003, the DNS port 53 is actually shut off and Windows is not listening on it? You can verify this by issuing from a DOS prompt:

telnet aa.bb.cc.dd 53

if a connection is established, then Windows is not really releasing the DNS port and SpamFilter may be getting "confused" as to if DNS is available or not, and we may need to investigate on what is really happening.


-------------
Roberto Franceschetti

http://www.logsat.com" rel="nofollow - LogSat Software

http://www.logsat.com/sfi-spam-filter.asp" rel="nofollow - Spam Filter ISP

Posted By: sirrar
Date Posted: 27 January 2005 at 9:34am

hi again

just tried to stop the DNS server and made a telnet to the dns server (same machine as spamfilter is installed on.)

It looks like windows 2003 is actually releasing the port.

Output from the test:

telnet 192.168.1.2 53
Connecting To 192.168.1.2...Could not open connection to the host, on port 53: C
onnect failed

192.168.1.2 is set to primary DNS server in spamfilter



-------------
Best regards...
Torsten Egebirk MCTIP: EA/SA - MCSE - MCSA - CCA - CCNA

Posted By: LogSat
Date Posted: 28 January 2005 at 12:20am
Torsten,

You were absolutely correct, we were able to duplicate the problem now. I believe we fixed it, and a pre-release patch is available in build 2.1.2.403 which we have just uploaded in the registered user area of the website. If you'd like to try it, please let us know if it fixes the problem in your environment as well.


-------------
Roberto Franceschetti

http://www.logsat.com" rel="nofollow - LogSat Software

http://www.logsat.com/sfi-spam-filter.asp" rel="nofollow - Spam Filter ISP

Posted By: sirrar
Date Posted: 28 January 2005 at 12:57am

Hi again

 

Just put in 403. Shut down the DNS service, and now Spamfilter is rotating to next DNS.

Problem solved.

Thankyou very much



-------------
Best regards...
Torsten Egebirk MCTIP: EA/SA - MCSE - MCSA - CCA - CCNA


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