<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv=Content-Type content="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 12 (filtered medium)">
<!--[if !mso]>
<style>
v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style>
<![endif]-->
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p
{mso-style-priority:99;
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
p.MsoAcetate, li.MsoAcetate, div.MsoAcetate
{mso-style-priority:99;
mso-style-link:"Balloon Text Char";
margin:0in;
margin-bottom:.0001pt;
font-size:8.0pt;
font-family:"Tahoma","sans-serif";}
span.BalloonTextChar
{mso-style-name:"Balloon Text Char";
mso-style-priority:99;
mso-style-link:"Balloon Text";
font-family:"Tahoma","sans-serif";}
span.balloontextchar0
{mso-style-name:balloontextchar;
mso-style-priority:99;
font-family:"Tahoma","sans-serif";}
span.balloontextchar00
{mso-style-name:balloontextchar0;
mso-style-priority:99;
font-family:"Tahoma","sans-serif";}
span.EmailStyle22
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.EmailStyle23
{mso-style-type:personal;
font-family:"Arial","sans-serif";
color:navy;}
span.EmailStyle24
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:#1F497D;}
span.EmailStyle25
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:#1F497D;}
span.EmailStyle26
{mso-style-type:personal;
font-family:"Arial","sans-serif";
color:navy;}
span.EmailStyle27
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.Section1
{page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=EN-US link=blue vlink=purple>
<div class=Section1>
<p class=MsoNormal><span style='color:#1F497D'>Thank you everyone for your
suggestions and input. <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>So just to clarify, the answer
to my question would be that the /etc/nsswitch.conf file tells the Linux box
how to resolve IP addresses. Mine says “hosts: files dns.” So
the Linux box consults “/etc/hosts” for the IP to name resolution
and if not found consults the dns server listed in “/etc/resolve.conf”.
<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>After it has resolved the name
then the packets get sent to SSH? If there is no name that resolves then
the IP address gets passed so there is no problem.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Then is the order name
resolution, iptables, then ssh if it is an ssh packet?<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<div>
<p class=MsoNormal><span style='color:#1F497D'>Denise Lopez<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
</div>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
redhat-sysadmin-list-bounces@redhat.com
[mailto:redhat-sysadmin-list-bounces@redhat.com] <b>On Behalf Of </b>Richard
Riley<br>
<b>Sent:</b> Thursday, October 25, 2007 12:55 PM<br>
<b>To:</b> redhat-sysadmin-list@redhat.com<br>
<b>Subject:</b> RE: SSH question<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>Denise,<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>If the windows machines do have static IP addresses, you can
eliminate the need to worry about AD or BIND by simply adding entries on the
servers in “/etc/hosts” for the windows machines. This way,
you control the hostname that will match the IP address and thus control what
hostname to use in your sshd_config entries.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'><o:p> </o:p></span></p>
<div>
<p><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1B6AB8'>Richard Riley</span></b><span style='color:navy'><br>
</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#666666'>System Administrator<br>
Email: rriley</span><span style='color:navy'><a
href="mailto:rgambotz@procuri.com"><span style='font-size:10.0pt;font-family:
"Arial","sans-serif";color:#666666'>@procuri.com</span></a><br>
<br>
</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#666666'>Procuri Inc.<br>
</span><span style='color:navy'><a href="http://www.procuri.com"><span
style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1B6AB8'>www.procuri.com</span></a><br>
<br>
</span><span style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:#999999'>The information contained in this message from Procuri Inc.,
including any attachments, is confidential and intended only for the named
recipient(s). If you have received this message in error, you are prohibited
from copying, distributing, or using the information. Please contact the sender
immediately by return email and delete the original message.</span><o:p></o:p></p>
</div>
<div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'>
<div>
<div class=MsoNormal align=center style='text-align:center'><span
style='font-size:12.0pt;font-family:"Times New Roman","serif"'>
<hr size=2 width="100%" align=center>
</span></div>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
redhat-sysadmin-list-bounces@redhat.com
[mailto:redhat-sysadmin-list-bounces@redhat.com] <b>On Behalf Of </b>Lopez,
Denise<br>
<b>Sent:</b> Thursday, October 25, 2007 2:56 PM<br>
<b>To:</b> redhat-sysadmin-list@redhat.com<br>
<b>Subject:</b> RE: SSH question</span><span style='font-size:12.0pt;
font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='color:#1F497D'>Thanks Jonathan,<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>We are running AD and
BIND. The windows clients look to AD for DNS. Our AD hosts our
internal DNS and BIND hosts external DNS. The SSH server also looks to AD
for DNS. For one admin station there is only a DNS entry in AD and the
other one there is a DNS entry in AD and an A record but no PTR record in BIND.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>My Linux box has NO entry in AD
or in BIND so the IP address doesn’t resolve and there is no problem. I
guess then my question is how does SSH handle DNS lookups?<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<div>
<p class=MsoNormal><span style='color:#1F497D'>Denise Lopez<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
</div>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
redhat-sysadmin-list-bounces@redhat.com
[mailto:redhat-sysadmin-list-bounces@redhat.com] <b>On Behalf Of </b>Martin,
Jonathan<br>
<b>Sent:</b> Thursday, October 25, 2007 5:47 AM<br>
<b>To:</b> redhat-sysadmin-list@redhat.com<br>
<b>Subject:</b> RE: SSH question<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>DHCP and "Register this connection in DNS" are
separate. You can specify static IPs in Windows and still have the server
dynamically register itself in DNS. The difference is with DHCP the DHCP
server (can) register the client's HOST record in DNS, but the client still
dynamically registers its PTR. Are you running Active Directory and
BIND? If your windows clients look to Windows for DNS and your SSH
server looks to BIND then you might have an issue of host and PTR records
not being in the right DNS.</span><span style='font-size:12.0pt;font-family:
"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>-Jonathan</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p> </o:p></span></p>
<div class=MsoNormal align=center style='text-align:center'><span
style='font-size:12.0pt;font-family:"Times New Roman","serif"'>
<hr size=2 width="100%" align=center>
</span></div>
<p class=MsoNormal style='margin-bottom:12.0pt'><b><span style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'> redhat-sysadmin-list-bounces@redhat.com
[mailto:redhat-sysadmin-list-bounces@redhat.com] <b>On Behalf Of </b>Holder,
Bill<br>
<b>Sent:</b> Wednesday, October 24, 2007 7:47 PM<br>
<b>To:</b> redhat-sysadmin-list@redhat.com<br>
<b>Subject:</b> RE: SSH question</span><span style='font-size:12.0pt;
font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Hi there,</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>
</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>you need to setup the dynamic DNS support in your DHCP client on
your Redhat boxes. I'm sorry I can't be more specific, it's been a while since I
did it, but I'm sure Google will point you at the information you need.</span><span
style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>/B</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p> </o:p></span></p>
<div class=MsoNormal align=center style='text-align:center'><span
style='font-size:12.0pt;font-family:"Times New Roman","serif"'>
<hr size=2 width="100%" align=center>
</span></div>
<p class=MsoNormal style='margin-bottom:12.0pt'><b><span style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'> redhat-sysadmin-list-bounces@redhat.com
[mailto:redhat-sysadmin-list-bounces@redhat.com] <b>On Behalf Of </b>Lopez,
Denise<br>
<b>Sent:</b> Thursday, 25 October 2007 9:44 AM<br>
<b>To:</b> redhat-sysadmin-list@redhat.com<br>
<b>Subject:</b> RE: SSH question</span><span style='font-size:12.0pt;
font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Thanks for your reply Richard,<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>The windows boxes are using DHCP
but they have static DHCP reservations because they are administrative boxes so
they always get the same IP address. <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>I think it has something to do
on the RHEL side and am just not sure what is happening.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<div>
<p class=MsoNormal><span style='color:#1F497D'>Denise Lopez<o:p></o:p></span></p>
</div>
<div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'>
<p class=MsoNormal><o:p> </o:p></p>
</div>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><br>
***********************************************************************<br>
The information in this e-mail together with any attachments is<br>
intended only for the person or entity to which it is addressed<br>
and may contain confidential and/or privileged material.<br>
Any form of review, disclosure, modification, distribution<br>
and/or publication of this e-mail message is prohibited. <br>
If you have received this message in error, you are asked to<br>
inform the sender as quickly as possible and delete this message<br>
and any copies of this message from your computer and/or your<br>
computer system network. <br>
Any attachments should be checked for viruses by you, before being opened.
SunWater accepts no responsibility for an attachment that contains a virus.<br>
***********************************************************************<o:p></o:p></span></p>
</div>
</div>
</body>
</html>