<div dir="ltr">And 5 for a falseticker fault protection:<div><br></div><div><i>"Note that four upstream time servers will protect you against only one falseticker. Using the 2n+1 algorithm, five upstreams will protect you against two falsetickers, seven will protect you against three falsetickers, etc....</i><div><i>Conventional wisdom is that using at least five upstream time servers would probably be a good idea, and you may want more."</i></div><div><br></div><div>Source: <a href="http://support.ntp.org/bin/view/Support/SelectingOffsiteNTPServers#Section_5.3.3">5.3.4. Excessive Number of Upstream Time Servers</a></div><br><div class="gmail_quote"><div dir="ltr">On Mon, May 8, 2017 at 9:49 AM Matthew Huff <<a href="mailto:mhuff@ox.com">mhuff@ox.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1f497d">If you are going to have local NTP servers, you will need 3 for a quorum. 4 for redundancy.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Courier New";color:#1f497d">Matthew Huff | 1 Manhattanville Rd</span><span style="font-size:11.0pt;font-family:"Courier New";color:#1f497d"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Courier New";color:#1f497d">Director of Operations | Purchase, NY 10577</span><span style="font-size:11.0pt;font-family:"Courier New";color:#1f497d"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Courier New";color:#1f497d">OTA Management LLC | Phone: <a href="tel:(914)%20460-4039" value="+19144604039" target="_blank">914-460-4039</a></span><span style="font-size:11.0pt;font-family:"Courier New";color:#1f497d"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Courier New";color:#1f497d">aim: matthewbhuff | Fax: <a href="tel:(914)%20694-5669" value="+19146945669" target="_blank">914-694-5669</a></span><span style="font-size:11.0pt;font-family:"Courier New";color:#1f497d"><u></u><u></u></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> cisco-voip [mailto:<a href="mailto:cisco-voip-bounces@puck.nether.net" target="_blank">cisco-voip-bounces@puck.nether.net</a>]
<b>On Behalf Of </b>Ryan Huff<br>
<b>Sent:</b> Monday, May 8, 2017 10:42 AM<br>
<b>To:</b> Ben Amick <bamick@HumanArc.com>; <a href="mailto:cisco-voip@puck.nether.net" target="_blank">cisco-voip@puck.nether.net</a><br>
<b>Subject:</b> Re: [cisco-voip] CCX and NTP<u></u><u></u></span></p>
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<p><span style="font-family:"Calibri",sans-serif;color:black">Hey Ben,<u></u><u></u></span></p>
<p><span style="font-family:"Calibri",sans-serif;color:black"><u></u> <u></u></span></p>
<p><span style="font-family:"Calibri",sans-serif;color:black">This has less to do with UCCX and more to do with the lack of time precision in Windows SNTP / NTP compared to the needs of UCOS. Yes, I know, die hard Redmond boys and girls will say that ever since
Win2003 that isn't the case but sorry, it is. (read: <a href="https://technet.microsoft.com/en-us/library/cc773013%28v=ws.10%29.aspx" target="_blank">
https://technet.microsoft.com/en-us/library/cc773013%28v=ws.10%29.aspx</a>). In fact, on page 84 (PDF page) of the latest SRND (<a href="http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/collab11/collab11.pdf" target="_blank">http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/collab11/collab11.pdf</a>)
Windows NTP is a flat nono for Cisco UC period.<u></u><u></u></span></p>
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<p><span style="font-family:"Calibri",sans-serif;color:black">IOS routers are great but here is how I like to roll (excuse the crudeness of the drawing, put it together this morning before coffee). I typically use Linux servers for NTP because they are so darn
useful for other utilitarian things ..... can't count how many times just having a Linux box on the network somewhere helped me out.<u></u><u></u></span></p>
<p><span style="font-family:"Calibri",sans-serif;color:black"><u></u> <u></u></span></p>
<p><span style="font-family:"Calibri",sans-serif;color:black"></span></p><img src="cid:15be9dc6aac4cff311" alt="image001.png" class="" style="max-width: 100%;"><u></u><u></u><p></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:black">= Ryan =
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black"> cisco-voip <<a href="mailto:cisco-voip-bounces@puck.nether.net" target="_blank">cisco-voip-bounces@puck.nether.net</a>>
on behalf of Ben Amick <<a href="mailto:bamick@HumanArc.com" target="_blank">bamick@HumanArc.com</a>><br>
<b>Sent:</b> Monday, May 8, 2017 10:12 AM<br>
<b>To:</b> <a href="mailto:cisco-voip@puck.nether.net" target="_blank">cisco-voip@puck.nether.net</a><br>
<b>Subject:</b> [cisco-voip] CCX and NTP</span><span style="font-family:"Calibri",sans-serif;color:black">
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<p><span style="font-family:"Calibri",sans-serif;color:black">What do you guys use for NTP on your CCX hosts? I’ve been informed by TAC that “CCX does not support Windows based NTP” so I was thinking about just pointing NTP towards my CCM hosts – is that a
valid scenario? I figure that since CCM is pretty much authoritative on everything for CCX as it is it wouldn’t be a problem?</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black"><u></u><u></u></span></p>
<p><span style="font-family:"Garamond",serif;color:black"> </span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black"><u></u><u></u></span></p>
<p><b><span style="font-size:10.0pt;font-family:"Garamond",serif;color:#3b3838">Ben Amick</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black"><u></u><u></u></span></p>
<p><span style="font-size:9.0pt;font-family:"Garamond",serif;color:#3b3838">Telecom Analyst</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black"><u></u><u></u></span></p>
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