DNS no response

  • Thread starter Thread starter Kevin D. Goodknecht [MVP]
  • Start date Start date
K

Kevin D. Goodknecht [MVP]

In peter <[email protected]> posted a question
Then Kevin replied below:
: Hi,
:
: I have a Windows 2000 SBS Server acting an Exchange server, Fax
: Server, DNS Server and Print Server. I have noticed a lot of disk
: activity from the HDD LED at times and sometimes I am unable send
: email as it says that it can not find the mail server (SMTP server
: from outside ISP)?
:
: It is a Intel 2.0G CPU with 512MB SD RAM. Should I add more RAM to
: this system?
:
: Thanks.
:
: PEter

Your Router or Firewall probably does not support EDNS0, Update them or
disable EDNS0 if an update is not available.
828731 - An External DNS Query May Cause an Error Message in Windows Server
2003
http://support.microsoft.com/default.aspx?scid=kb;en-us;828731&Product=winsvr2003
 
Hi,

I have a Windows 2000 SBS Server acting an Exchange server, Fax Server, DNS
Server and Print Server. I have noticed a lot of disk activity from the HDD
LED at times and sometimes I am unable send email as it says that it can not
find the mail server (SMTP server from outside ISP)?

It is a Intel 2.0G CPU with 512MB SD RAM. Should I add more RAM to this
system?

Thanks.

PEter
 
In
Kevin D. Goodknecht said:
In

Your Router or Firewall probably does not support EDNS0, Update them
or
disable EDNS0 if an update is not available.
828731 - An External DNS Query May Cause an Error Message in Windows
Server 2003
http://support.microsoft.com/default.aspx?scid=kb;en-us;828731&Product=winsvr2003

--
Best regards,
Kevin D4 Dad Goodknecht Sr. [MVP]
Hope This Helps
============================
Click to expand...

I would increase the RAM to at least 1gig, but it has nothing to do with DNS
not responding or not finding a host.

In addition to the EDNS0 issue, I'm curious WHAT mail server it's trying to
find? If Peter can give us more info, maybe we can pinpoint it. Does this
happen with every piece of mail or is it selective?

Yahoo.com, for example, is one domain that will not resolve if using EDNS0.


--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.
This posting is provided "AS IS" with no warranties.

Ace Fekay, MCSE 2000, MCSE+I, MCSA, MCT, MVP
Microsoft Windows MVP - Active Directory
 
Hello All,


Just out of curiosity, what kind of router and/or firewall do you have in
place? I doubt if you have the EDNS0 issue as it pertains to W23K DNS
servers.

Basically W23K DNS servers will negotiate EDNS0 support with other DNS
servers. If the negotiation is successful, then UDP packets of larger than
512 are used. If a firewall doesn't play nice with the UDP packet size, it
is dropped.

EDNS0

828263 DNS query responses do not travel through a firewall in Windows
Server
http://support.microsoft.com/?id=828263

828731 An External DNS Query May Cause an Error Message in Windows Server
2003
http://support.microsoft.com/?id=828731

832223 Some DNS Name Queries Are Unsuccessful After You Upgrade Your DNS
Server
http://support.microsoft.com/?id=832223

Link
http://www.microsoft.com/technet/treeview/default.asp?url=/technet/prodtechn
ol/windowsserver2003/proddocs/standard/sag_DNS_imp_EDNSsupport.asp


Questions
************
What service pack level is the server?
Do you notice a direct correlation in resource spikes vs. the mail failure?
Mail stops flowing the exact time the HDD lights up or processor spikes?
When mail stops can you still resolve the MX record via nslookup?
Does mail flow if you were to restart the DNS service?
Does mail flow if you clear the DNS cache?



Shane Brasher
MCSE (2003,2000,NT),MCSA, A+
Microsoft Platforms Support
Windows NT/2000 Networking
 
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