--- On <b>Wed, 5/19/10, Ed Knapp <i>&lt;<a href="mailto:catbertek@hotmail.com" target="_blank">catbertek@hotmail.com</a>&gt;</i></b> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="font: inherit;" valign="top"><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><br>From: Ed Knapp &lt;<a href="mailto:catbertek@hotmail.com" target="_blank">catbertek@hotmail.com</a>&gt;<div class="im">
<br>Subject: Re: load balanced configuration<br>To: &quot;Main PLUG discussion list&quot; &lt;<a href="mailto:plug-discuss@lists.plug.phoenix.az.us" target="_blank">plug-discuss@lists.plug.phoenix.az.us</a>&gt;<br></div>Date: Wednesday, May 19, 2010, 6:09 PM<div>
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<font face="Calibri, Verdana, Helvetica, Arial"><span style="font-size: 11pt;">One thing struck me here with your description...<br>
<br>
“and a change to the DNS and we are off and running”<br>
<br>
While your DNS records might be changed relatively quickly during an incident, the change<br>
Itself can take quite a while to trickle down to the end users/clients out in the cloud.<br>
Any client’s DNS resolution that has not expired in the cache nor manually refreshed will<br>
still fail to properly resolve/connect.  It doesn’t usually, but I tell clients to plan for 48 hours<br>
Estimated time for the change to completely propagate.</span></font><br></div></div></div></blockquote></td></tr></tbody></table></blockquote></div>Some DNS services like UltraDNS can have your TTL set as low as 5 minutes so you can change addresses quickly.  There are still some providers that ignore the time to live setting though and cache answers longer.<br>
<br><br>