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Meyric

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We've started to see an odd issue on out Kerio Connect server.

Every few minutes the DNS lookup will fail. With the DNS resolver debug log enabled we see:

'No nameservers found'

I've tried multiple local DNS and external DNS and the issue remains. I've also confirmed that the server Connect runs on is not loosing network connection and can always lookup the same DNS entries from the command line.

The Kerio DNS resolver will then carry on as normal and then again after an few minutes will fail.

This is causing delays for us.

Heres a sample log:

02/Jul/2013 15:03:29][5220159488] {dns} Cannot resolve query for name <removed>
[02/Jul/2013 15:03:29][5220159488] {dns} Searching cache for A records for host <removed>
[02/Jul/2013 15:03:29][5220159488] {dns} Searching DNS for A records for host <removed>
[02/Jul/2013 15:03:29][5220159488] {dns} Querying server no. 1, address x.x.x.x
[02/Jul/2013 15:03:29][5220159488] {dns} Querying server no. 2, address 8.8.8.8
[02/Jul/2013 15:03:29][5220159488] {dns} Querying server no. 3, address 8.8.4.4
[02/Jul/2013 15:03:29][5220159488] {dns} No nameservers found

x.x.x.x being our internal DNS and the other two Google Public DNS.

When the DNS resolver works it always users our internal one.

When the DNS resolver fails it fails on both internal and external.

The Server is Mac OS 10.6.8 Server and Kerio Connect 8.1.2.

Anyone have an idea what is happening here?

Thanks.
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tonyswu

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What DNS servers do your internal DNS servers do recursive lookup to? Sounds like you've ruled out other clients, but is there any other computer within the same network that's having this issue?
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Pavel Dobry (Kerio)

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[Updated on: Tue, 02 July 2013 18:18]


Knowledge Base: http://kb.kerio.com/.
Technical support: http://www.kerio.com/support
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Meyric

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Our internal DNS uses the same Google public 8.8.8.8 and 8.8.4.4.

I have seen no instances of failed lookups on other clients on the network. The log message implies kerio cannot connect to any of the 3 DNS servers which is why this is so odd.

I have restart Connect in 32bit and will monitor.

[Updated on: Wed, 03 July 2013 10:34]

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Meyric

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Switching to 32bit process seems to have done the trick, thank you.

Pavel, can you give me some insight into why this resolved the issue and whether it be fixed in later version of Connect?

As I understand it, I will have to change the Launch Daemon plist every upgrade?
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Pavel Dobry (Kerio)

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We are still investigating this issue.

Knowledge Base: http://kb.kerio.com/.
Technical support: http://www.kerio.com/support
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kirbyl

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I am experiencing the same issue but on a Windows server. Does switching back to 32 bit on a Windows box work as well?
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Pavel Dobry (Kerio)

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No. It does not help on Windows.
Similar issues are usually caused by changes on network interfaces made by management softwares provided by server vendor. We've seen it with Dell utilities for example.

Knowledge Base: http://kb.kerio.com/.
Technical support: http://www.kerio.com/support
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mkassar

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Well we can safely add to this article that in Kerio 8.2.2 on Mac OS X server 10.6.8 we have been experiencing the same issue and applying the same 32 bit workaround does in fact fix the issue.
I hope Kerio will fix this in a future update.



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Meyric

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We just updated to 8.2.2 and the issue continues.

Can anyone from Kerio confirm this - we are still suffering from this issue and running in 32bit mode is starting to get tight with memory.

We Also run Mac OS 10.6.8 - can anyone confirm that a later version of Mac OS resolves the issue?

Pavel says 'We are still investigating this issue.' - can we get the results of this investigation please.
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mkassar

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I have been informed this is in fact a bug and the Kerio team is working hard to fix it.
Meanwhile the 32 bit mode of Kerio is causing us untold grief...with the temp file bloating issue. The file gets as high at 5TB and we need to constantly babysit the server to ensure it doesn't happen. even so it has happened 5 times in the last two weeks..ugh!

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giobbi

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Same problem here.
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neilticktin

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Kerio: Can you give an update on this issue? Has it been resolved in the current version?

I'm seeing this problem on specific domains, but not most. (See below -- names scrubbed).
Thanks!

Neil



This is just a temporary error. The server will continue to attempt to deliver
the message. If the message cannot be delivered in the defined time limit you will
be informed again.
Reporting-MTA: dns; mail.mydomain.com
Arrival-Date: Tue, 23 Dec 2014 09:54:36 -0800

Original-Recipient: namechanged<_at_>hotmail.com
Final-Recipient: rfc822; namechanged<_at_>hotmail.com
Action: delayed
Status: 4.4.3
Diagnostic-Code: DNS; DNS lookup failed

Original-Recipient: namechanged2<_at_>hotmail.com
Final-Recipient: rfc822; namechanged2<_at_>hotmail.com
Action: delayed
Status: 4.4.3
Diagnostic-Code: DNS; DNS lookup failed

Original-Recipient: namechanged3<_at_>mit.edu
Final-Recipient: rfc822; namechanged3<_at_>mit.edu
Action: delayed
Status: 4.4.3
Diagnostic-Code: DNS; DNS lookup failed
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