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Howard Wilkinson wrote:
<blockquote cite="mid:48592D16.6010001@cohtech.com" type="cite">
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<title>Re: DNS: Question about setting abc.com record</title>
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<p><font size="2">Daniel B. Thurman wrote:</font>
<br>
<font size="2">></font>
<br>
<font size="2">> I have several DNS servers and wondered if the
following</font>
<br>
<font size="2">> record entry is properly set for all of my DNS
servers:</font>
<br>
<font size="2">></font>
<br>
<font size="2">> $TTL 172800</font>
<br>
<font size="2">> @ IN SOA ns1.abc.com. admin.abc.com. (</font>
<br>
<font size="2">> 1 ; serial</font>
<br>
<font size="2">> 3H ; refresh</font>
<br>
<font size="2">> 15M ; retry</font>
<br>
<font size="2">> 1W ; expiry</font>
<br>
<font size="2">> 1D ) ; minimum</font>
<br>
<font size="2">> ;============ Nameserver ================</font>
<br>
<font size="2">> @ IN NS ns1.abc.com.</font>
<br>
<font size="2">> @ IN NS ns2.abc.com.</font>
<br>
<font size="2">> @ IN NS ns3.abc.com.</font>
<br>
<font size="2">> ;============ Mail Exchange =============</font>
<br>
<font size="2">> @ IN MX 10 mail1.abc.com.</font>
<br>
<font size="2">> @ IN MX 20 mail2.abc.com.</font>
<br>
<font size="2">> @ IN MX 30 mail3.abc.com.</font>
<br>
<font size="2">> @ IN TXT v=spf1 a mx -all</font>
<br>
<font size="2">> ;============ Hosts ======================</font>
<br>
<font size="2">> @ IN A 10.1.0.1</font>
<br>
<font size="2">> mail1 IN A 10.1.0.1</font>
<br>
<font size="2">> mail2 IN A 10.1.0.2</font>
<br>
<font size="2">> mail3 IN A 10.1.0.3</font>
<br>
<font size="2">> ns1 IN A 10.1.0.1</font>
<br>
<font size="2">> ns2 IN A 10.1.0.2</font>
<br>
<font size="2">> ns3 IN A 10.1.0.2</font>
<br>
<font size="2">> ;========================================</font>
<br>
<font size="2">></font>
<br>
<font size="2">> In particular, I am focusing on record:</font>
<br>
<font size="2">> @ IN A 10.1.0.1</font>
<br>
<font size="2">></font>
<br>
<font size="2">> The reason I have set all of my DNS zones for the
above record</font>
<br>
<font size="2">> for all of my DNS servers is because if had I set
this record for the</font>
<br>
<font size="2">> actual localhost IP address, it appears that if I
send mail on the</font>
<br>
<font size="2">> localhost, the localhost would receive the email
I sent. For example,</font>
<br>
<font size="2">> sending mail to: <a class="moz-txt-link-abbreviated" href="mailto:joe@abc.com">joe@abc.com</a> would be received at
the localhost instead</font>
<br>
<font size="2">> of being sent to mail{1,2,3}.abc.com. Worse, any
localhost programs</font>
<br>
<font size="2">> attempting to send emails to <a class="moz-txt-link-rfc2396E" href="mailto:root@abc.com">"root@abc.com"</a> would
fail to be delivered</font>
<br>
<font size="2">> to one of the MX list.</font>
<br>
<font size="2">></font>
<br>
<font size="2">> So, the question is, must each DNS server have
it's own real IP address</font>
<br>
<font size="2">> in the '@' record? If so, how do I get around
this?</font>
<br>
<font size="2">></font>
<br>
<font size="2">> Kind regards,</font>
<br>
<font size="2">> Dan</font>
<br>
<font size="2">></font>
<br>
<font size="2">Dan,</font>
</p>
<p><font size="2">do you have any other services with the network
address 10.1.0.1 which </font>
<br>
<font size="2">you want to refer to as 'abc.com'? If not you do not
need the 'A' record </font>
<br>
<font size="2">just after the Hosts line. Otherwise for a simple
internal network this </font>
<br>
<font size="2">look reasonable. However, do you not have any other
hosts you need to </font>
<br>
<font size="2">address? If so the you need their 'A' records.</font>
</p>
<p><font size="2">Howard.</font>
</p>
</blockquote>
Yes, I have services at 10.1.0.1 as well as at several other<br>
hosts. The main reason that I use the @ is so that I can<br>
use 'abc.com' such as <a class="moz-txt-link-abbreviated" href="mailto:dan@abc.com">dan@abc.com</a> or to simply type<br>
abc.com in the web-browser's URL line and it would get<br>
resolved.<br>
<br>
What I found was, if I was at host one.abc.com, which had<br>
a DNS server and had @ record set to it's own IP address,<br>
and a local account "dan", sending mail to <a class="moz-txt-link-abbreviated" href="mailto:dan@abc.com">dan@abc.com</a><br>
would be received locally instead of being delivered<br>
according to the MX records. That is why I set the @<br>
record for all of my DNS servers to the same IP address<br>
and not to each DNS servers actual IP address.<br>
<br>
Does this make sense?<br>
<br>
Thanks!<br>
Dan<br>
<br>
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