<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=us-ascii">
<META content="MSHTML 6.00.2900.3354" name=GENERATOR></HEAD>
<BODY>
<DIV><FONT face=Arial size=2><SPAN
class=041222421-08082008>Hi,</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I have a domain hosted at a third party site called
my.domain.com.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>In my company's zone file, we have NS records that
refer to this third<SPAN class=041222421-08082008> </SPAN>party hosting site,
and we have an 'A' record set up that associates the my.domain.com domain
to <SPAN class=041222421-08082008>the IP address of </SPAN>a load balancer
that balances traffic </FONT><FONT face=Arial size=2>coming into the site
between two web servers, all in a DMZ. We also have an MX record<SPAN
class=041222421-08082008> </SPAN>that refers the my.domain.com to a mail server
host, also in the DMZ. Finally,<SPAN class=041222421-08082008> </SPAN>we
have PTR records that refer back to the load balancer and mail server
hosts.<BR>All this is set up correctly, everything works, and all DNS checks
pass.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I need to add a subdomain, call it
sub.my.domain.com, and I would like to associate the subdomain to the same load
balancer if possible. What is the best<SPAN class=041222421-08082008>
</SPAN>way to do this without disrupting the incoming traffic to the primary
domain or<BR>the flow of incoming SMTP traffic to the<SPAN
class=041222421-08082008> </SPAN>mail server? Is it best in this situation
to use a CNAME to map the subdomain, or to use a whole new 'A' record? If
I create a new<SPAN class=041222421-08082008> </SPAN>'A' record, I would not
want to add a new PTR record for the sub.my.domain.com as the<SPAN
class=041222421-08082008> </SPAN>IP address would be the same as the PTR that
refers back to my.domain.com. This I <BR>believe, would cause DNS checks on my
mail server to fail, since there would be<SPAN class=041222421-08082008>
</SPAN>two hostnames associated with the same IP address.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Your help is appreciated!</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><SPAN class=041222421-08082008><FONT face=Arial size=2>
<DIV align=left><FONT face=Arial size=2>Bill</FONT></DIV>
<DIV align=left><FONT face=Arial size=2></FONT></DIV>
<DIV align=left><FONT face=Arial
size=2></FONT> </DIV></FONT></SPAN></DIV></BODY></HTML>