<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">
Thank you…this is very useful information; I thought TTL could only be specified on a per-zone basis, not per-host.<br class="">
<div><br class="">
<blockquote type="cite" class="">
<div class="">On Jun 25, 2021, at 11:10 AM, Richard T.A. Neal <<a href="mailto:richard@richardneal.com" class="">richard@richardneal.com</a>> wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
<div class="">Hi Bruce,<br class="">
<br class="">
Here you're specifying a distinct TTL for those records which overrides the default TTL for this zone (which you will have set towards the top of the file with the rest of the defaults)<br class="">
<br class="">
1m = 60 seconds:<br class="">
<a href="https://web.mit.edu/rhel-doc/5/RHEL-5-manual/Deployment_Guide-en-US/s1-bind-zone.html" class="">https://web.mit.edu/rhel-doc/5/RHEL-5-manual/Deployment_Guide-en-US/s1-bind-zone.html</a><br class="">
<br class="">
So you're essentially telling DNS clients that the value provided for mail.{your-fqdn} is only valid for 60 seconds. As you say, a cheap load balancing attempt!<br class="">
<br class="">
Best,<br class="">
<br class="">
Richard.<br class="">
<br class="">
-----Original Message-----<br class="">
From: bind-users <bind-users-bounces@lists.isc.org> On Behalf Of Bruce Johnson<br class="">
Sent: 25 June 2021 6:56 pm<br class="">
To: bind-users@lists.isc.org<br class="">
Subject: Odd A record in our hosts zone file<br class="">
<br class="">
I ran across these A records in one of our zone files:<br class="">
<br class="">
;EXCHANGE STUFF<br class="">
mail 1m IN A xxx.xxx.xxx.52; dhbex1<br class="">
mail 1m IN A xxx.xxx.xxx.54; dhbex2<br class="">
<br class="">
I can see that this is a cheap load-balancing for our exchange OWA servers, but what is the ‘1m’ notation? I haven’t been able to find that in my searching of the manual.<br class="">
<br class="">
(We’re adding new servers and I need to make sure our DNS is properly set for them.)<br class="">
<br class="">
-- <br class="">
Bruce Johnson<br class="">
University of Arizona<br class="">
College of Pharmacy<br class="">
Information Technology Group<br class="">
<br class="">
Institutions do not have opinions, merely customs<br class="">
<br class="">
_______________________________________________<br class="">
Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list<br class="">
<br class="">
ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information.<br class="">
<br class="">
<br class="">
bind-users mailing list<br class="">
bind-users@lists.isc.org<br class="">
https://lists.isc.org/mailman/listinfo/bind-users<br class="">
_______________________________________________<br class="">
Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list<br class="">
<br class="">
ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information.<br class="">
<br class="">
<br class="">
bind-users mailing list<br class="">
bind-users@lists.isc.org<br class="">
https://lists.isc.org/mailman/listinfo/bind-users<br class="">
</div>
</div>
</blockquote>
</div>
<br class="">
<div class=""><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; ">
<div class="">-- <br class="">
Bruce Johnson<br class="">
University of Arizona<br class="">
College of Pharmacy<br class="">
Information Technology Group<br class="">
<br class="">
Institutions do not have opinions, merely customs</div>
</span></div>
<br class="">
</body>
</html>