Date: Mon, 15 Oct 2001 07:51:01 -0700 From: Sean Mathias <SeanM@prosolve.com> To: "'Drew J. Weaver'" <drew.weaver@thenap.com> Cc: "'freebsd-net@FreeBSD.ORG'" <freebsd-net@FreeBSD.ORG> Subject: RE: DNS causing problems with sendmail? Message-ID: <CD855A91DC3CD411BEB20050DA2CB7D10765D5@fs01.prosolve.com>
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This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------_=_NextPart_001_01C15588.CE86D2A0 Content-Type: text/plain; charset="iso-8859-1" I have seen a similar timeout problem, though not with dial up. The problem was with the ident protocol talking to other mail servers. When I turned off this check, performance improved greatly. In the sendmail.cf file, I changed the ident timeout to zero to disable it. O Timeout.ident=0s Hope this helps, Sean Mathias Network & Security Consultant Prosolve http://www.prosolve.com <http://www.prosolve.com/>; v. (206) 306-2525 f. (206) 306-2526 -----Original Message----- From: Drew J. Weaver [mailto:drew.weaver@thenap.com] Sent: Monday, October 15, 2001 5:41 AM To: 'freebsd-net@freebsd.org' Subject: DNS causing problems with sendmail? 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 ------_=_NextPart_001_01C15588.CE86D2A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML xmlns=3D"http://www.w3.org/TR/REC-html40" xmlns:o =3D=20 "urn:schemas-microsoft-com:office:office" xmlns:w =3D=20 "urn:schemas-microsoft-com:office:word"><HEAD> <META HTTP-EQUIV=3D"Content-Type" CONTENT=3D"text/html; = charset=3Diso-8859-1"> <META content=3DWord.Document name=3DProgId> <META content=3D"MSHTML 5.50.4616.200" name=3DGENERATOR> <META content=3D"Microsoft Word 10" name=3DOriginator><LINK=20 href=3D"cid:filelist.xml@01C15554.7FB310A0" rel=3DFile-List><!--[if gte = mso 9]><xml> <o:OfficeDocumentSettings> <o:DoNotRelyOnCSS/> </o:OfficeDocumentSettings> </xml><![endif]--><!--[if gte mso 9]><xml> <w:WordDocument> <w:SpellingState>Clean</w:SpellingState> <w:GrammarState>Clean</w:GrammarState> <w:DocumentKind>DocumentEmail</w:DocumentKind> <w:EnvelopeVis/> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--> <STYLE>@page Section1 {size: 8.5in 11.0in; margin: 1.0in 1.25in 1.0in = 1.25in; mso-header-margin: .5in; mso-footer-margin: .5in; = mso-paper-source: 0; } P.MsoNormal { FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman"; = mso-style-parent: ""; mso-pagination: widow-orphan; = mso-fareast-font-family: "Times New Roman" } LI.MsoNormal { FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman"; = mso-style-parent: ""; mso-pagination: widow-orphan; = mso-fareast-font-family: "Times New Roman" } DIV.MsoNormal { FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman"; = mso-style-parent: ""; mso-pagination: widow-orphan; = mso-fareast-font-family: "Times New Roman" } A:link { COLOR: blue; TEXT-DECORATION: underline; text-underline: single } SPAN.MsoHyperlink { COLOR: blue; TEXT-DECORATION: underline; text-underline: single } A:visited { COLOR: purple; TEXT-DECORATION: underline; text-underline: single } SPAN.MsoHyperlinkFollowed { COLOR: purple; TEXT-DECORATION: underline; text-underline: single } SPAN.EmailStyle17 { COLOR: windowtext; FONT-FAMILY: Arial; mso-style-type: = personal-compose; mso-style-noshow: yes; mso-ansi-font-size: 10.0pt; = mso-bidi-font-size: 10.0pt; mso-ascii-font-family: Arial; = mso-hansi-font-family: Arial; mso-bidi-font-family: Arial } SPAN.SpellE { mso-style-name: ""; mso-spl-e: yes } SPAN.GramE { mso-style-name: ""; mso-gram-e: yes } DIV.Section1 { page: Section1 } </STYLE> <!--[if gte mso 10]> <style> /* Style Definitions */=20 table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} </style> <![endif]--></HEAD> <BODY lang=3DEN-US style=3D"tab-interval: .5in" vLink=3Dpurple = link=3Dblue> <DIV><SPAN class=3D655064914-15102001><FONT face=3DArial = color=3D#0000ff size=3D2>I have=20 seen a similar timeout problem, though not with dial up. The = problem was=20 with the ident protocol talking to other mail servers. When I = turned off=20 this check, performance improved greatly. </FONT></SPAN></DIV> <DIV><SPAN class=3D655064914-15102001><FONT face=3DArial = color=3D#0000ff=20 size=3D2></FONT></SPAN> </DIV> <DIV><SPAN class=3D655064914-15102001><FONT face=3DArial = color=3D#0000ff size=3D2>In the=20 sendmail.cf file, I changed the ident timeout to zero to disable=20 it.</FONT></SPAN></DIV> <DIV><SPAN class=3D655064914-15102001><FONT face=3DArial = color=3D#0000ff=20 size=3D2></FONT></SPAN> </DIV> <DIV><SPAN class=3D655064914-15102001><FONT face=3DArial = color=3D#0000ff size=3D2>O=20 Timeout.ident=3D0s</FONT></SPAN></DIV> <DIV><SPAN class=3D655064914-15102001><FONT face=3DArial = color=3D#0000ff=20 size=3D2></FONT></SPAN> </DIV> <DIV><SPAN class=3D655064914-15102001><FONT face=3DArial = color=3D#0000ff size=3D2>Hope=20 this helps,</FONT></SPAN></DIV> <DIV><SPAN class=3D655064914-15102001><FONT face=3DArial = color=3D#0000ff=20 size=3D2></FONT></SPAN> </DIV> <DIV><SPAN class=3D655064914-15102001> <P><B><FONT face=3DArial size=3D2>Sean Mathias</FONT></B> <BR><FONT = face=3DArial=20 size=3D1>Network & Security Consultant</FONT> <BR><FONT = face=3DArial=20 size=3D1>Prosolve</FONT> <BR><FONT face=3DArial size=3D1><A = target=3D_blank=20 href=3D"http://www.prosolve.com/">http://www.prosolve.com</A></FONT>; = <BR><FONT=20 face=3DArial size=3D1>v. (206) 306-2525</FONT> <BR><FONT face=3DArial = size=3D1>f. (206)=20 306-2526</FONT> </P></SPAN></DIV> <BLOCKQUOTE dir=3Dltr style=3D"MARGIN-RIGHT: 0px"> <DIV class=3DOutlookMessageHeader dir=3Dltr align=3Dleft><FONT = face=3DTahoma=20 size=3D2>-----Original Message-----<BR><B>From:</B> Drew J. Weaver=20 [mailto:drew.weaver@thenap.com]<BR><B>Sent:</B> Monday, October 15, = 2001 5:41=20 AM<BR><B>To:</B> 'freebsd-net@freebsd.org'<BR><B>Subject:</B> DNS = causing=20 problems with sendmail?<BR><BR></FONT></DIV> <DIV class=3DSection1> <P class=3DMsoNormal style=3D"TEXT-INDENT: 0.5in"><FONT face=3DArial = size=3D2><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: Arial">Hi, I've had this = problem for a=20 few days now, we have a small dial-up ISP and when users dial into = one of our=20 cities they get a 209.xxx.xxx.xxx IP and our mail server responds = normally, we=20 have another modem pool in that city that consists of 206.xxx.xxx.xxx = IP=20 addresses, if a user gets a 206.xxx.xxx.xxx IP address and they = attempt to=20 check mail it takes a good 2-3 minutes before the <SPAN=20 class=3DSpellE>sendmail</SPAN> connection starts, which is an obvious = problem=20 because of the timeouts on email clients (and.. 2-3 minutes is just = bad). I've=20 been <SPAN class=3DSpellE>kinda</SPAN> asking around on <SPAN=20 class=3DSpellE>comp.mail.sendmail</SPAN> about this issue and they = are telling=20 me it is a DNS problem. Well, I know that my mail server can reverse = the IP=20 addresses because if I am logged in and issue a host command with the = IP after=20 it the server is able to produce the proper reverse name. Another = user thought=20 it was because I have no Forward <SPAN class=3DSpellE>dns</SPAN> (a = record) for=20 what the <SPAN class=3DSpellE>IPs</SPAN> are reversed to, but the = fact is I've=20 NEVER had any <SPAN class=3DGramE>A</SPAN> records or anything for my = modem=20 pools. I also have another server running the same version of <SPAN=20 class=3DSpellE>sendmail</SPAN>, and if I dial into this city and get = a=20 206.xxx.xxx.xxx IP and telnet to port 25 on that server it comes up = instantly.=20 So this appears to be an issue only effecting one daemon on one = server. The=20 afflicted server also runs a POP daemon that isn't having any = problems of this=20 type.<o:p></o:p></SPAN></FONT></P> <P class=3DMsoNormal style=3D"TEXT-INDENT: 0.5in"><FONT face=3DArial = size=3D2><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: = Arial"><o:p> </o:p></SPAN></FONT></P> <P class=3DMsoNormal style=3D"TEXT-INDENT: 0.5in"><FONT face=3DArial = size=3D2><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: Arial">Does anyone have a clue = on this?=20 I'm awfully confused at this point.<o:p></o:p></SPAN></FONT></P> <P class=3DMsoNormal style=3D"TEXT-INDENT: 0.5in"><FONT face=3DArial = size=3D2><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: = Arial"><o:p> </o:p></SPAN></FONT></P> <P class=3DMsoNormal style=3D"TEXT-INDENT: 0.5in"><FONT face=3DArial = size=3D2><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: = Arial">Thanks,<o:p></o:p></SPAN></FONT></P> <P class=3DMsoNormal style=3D"TEXT-INDENT: 0.5in"><FONT face=3DArial = size=3D2><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: = Arial">-Drew<o:p></o:p></SPAN></FONT></P> <P class=3DMsoNormal style=3D"TEXT-INDENT: 0.5in"><FONT face=3DArial = size=3D2><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: = Arial"><o:p> </o:p></SPAN></FONT></P></DIV></BLOCKQUOTE></BODY></HT= ML> ------_=_NextPart_001_01C15588.CE86D2A0-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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