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Date:      Mon, 15 Oct 2001 08:40:46 -0400
From:      "Drew J. Weaver" <drew.weaver@thenap.com>
To:        "'freebsd-net@freebsd.org'" <freebsd-net@freebsd.org>
Subject:   DNS causing problems with sendmail?
Message-ID:  <B1A7D9973EBED3119ADD009027DC86492B16CF@MAILMAN>

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[-- Attachment #1 --]
Hi, I've had this problem for a few days now, we have a small dial-up ISP
and when users dial into one of our cities they get a 209.xxx.xxx.xxx IP and
our mail server responds normally, we have another modem pool in that city
that consists of 206.xxx.xxx.xxx IP addresses, if a user gets a
206.xxx.xxx.xxx IP address and they attempt to check mail it takes a good
2-3 minutes before the sendmail connection starts, which is an obvious
problem because of the timeouts on email clients (and.. 2-3 minutes is just
bad). I've been kinda asking around on comp.mail.sendmail about this issue
and they are telling me it is a DNS problem. Well, I know that my mail
server can reverse the IP addresses because if I am logged in and issue a
host command with the IP after it the server is able to produce the proper
reverse name. Another user thought it was because I have no Forward dns (a
record) for what the IPs are reversed to, but the fact is I've NEVER had any
A records or anything for my modem pools. I also have another server running
the same version of sendmail, and if I dial into this city and get a
206.xxx.xxx.xxx IP and telnet to port 25 on that server it comes up
instantly. So this appears to be an issue only effecting one daemon on one
server. The afflicted server also runs a POP daemon that isn't having any
problems of this type.
 
Does anyone have a clue on this? I'm awfully confused at this point.
 
Thanks,
-Drew
 

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<p class=MsoNormal style='text-indent:.5in'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Hi, I've had this problem for
a few days now, we have a small dial-up ISP and when users dial into one of our
cities they get a 209.xxx.xxx.xxx IP and our mail server responds normally, we
have another modem pool in that city that consists of 206.xxx.xxx.xxx IP
addresses, if a user gets a 206.xxx.xxx.xxx IP address and they attempt to
check mail it takes a good 2-3 minutes before the <span class=SpellE>sendmail</span>
connection starts, which is an obvious problem because of the timeouts on email
clients (and.. 2-3 minutes is just bad). I've been <span class=SpellE>kinda</span>
asking around on <span class=SpellE>comp.mail.sendmail</span> about this issue
and they are telling me it is a DNS problem. Well, I know that my mail server
can reverse the IP addresses because if I am logged in and issue a host command
with the IP after it the server is able to produce the proper reverse name.
Another user thought it was because I have no Forward <span class=SpellE>dns</span>
(a record) for what the <span class=SpellE>IPs</span> are reversed to, but the
fact is I've NEVER had any <span class=GramE>A</span> records or anything
for my modem pools. I also have another server running the same version of <span
class=SpellE>sendmail</span>, and if I dial into this city and get a
206.xxx.xxx.xxx IP and telnet to port 25 on that server it comes up instantly. So
this appears to be an issue only effecting one daemon on one server. The
afflicted server also runs a POP daemon that isn't having any problems of
this type.<o:p></o:p></span></font></p>

<p class=MsoNormal style='text-indent:.5in'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal style='text-indent:.5in'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Does anyone have a clue on this? I'm
awfully confused at this point.<o:p></o:p></span></font></p>

<p class=MsoNormal style='text-indent:.5in'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal style='text-indent:.5in'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Thanks,<o:p></o:p></span></font></p>

<p class=MsoNormal style='text-indent:.5in'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>-Drew<o:p></o:p></span></font></p>

<p class=MsoNormal style='text-indent:.5in'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

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