<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=Windows-1252">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]--><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
.MsoChpDefault
{mso-style-type:export-only;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style>
</head>
<body lang="EN-US" link="blue" vlink="#954F72">
<div class="WordSection1">
<p class="MsoNormal">As I recall, from the last time I had the occasion to deal with an ATA; I think port 1 uses the device’s media access code, and is what ultimately gets resolved into the ARP table. From a network perspective, I don’t think any thing/scanner
could ever “see” a non-cisco device on the network due to this method (which is why I believe Cisco may have chose this behavior), short of what you’ve done here by manually looking up the ‘spoofed’ OUI that is reported by RIS in the CCM GUI.</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I believe, if I’m not mistaken, the ATA uses <i>software magic</i> to register/communicate port 2 with a shifted/appended MAC address to “play nice” with CCM’s unique device name requirement. I could be entirely wrong though; I’m basing
my statements off of dated experience (I haven’t used an ATA in close to a year) and I don’t have an ATA at the ready to test with.</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Ryan<o:p></o:p></p>
<div style="mso-element:para-border-div;border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal" style="border:none;padding:0in"><b>From: </b><a href="mailto:avholloway+cisco-voip@gmail.com">Anthony Holloway</a><br>
<b>Sent: </b>Tuesday, May 22, 2018 12:54 PM<br>
<b>To: </b><a href="mailto:ryanhuff@outlook.com">Ryan Huff</a><br>
<b>Cc: </b><a href="mailto:jonfoxipt@gmail.com">Jon Fox</a>; <a href="mailto:cisco-voip@puck.nether.net">
cisco-voip@puck.nether.net</a><br>
<b>Subject: </b>Re: [cisco-voip] ATA190</p>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Aren't the first few values of a MAC tied to the vendor? If so, does this trick make it look like the second port is a different vendor product? And if so, it would be funny if it was a competitor.
<o:p></o:p></p>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Ah, but no such luck today.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal"><img border="0" width="339" height="317" style="width:3.5312in;height:3.302in" id="Picture_x0020_3" src="cid:ii_jhhx33e01_16388c3b26b144f0" alt="cid:ii_jhhx33e01_16388c3b26b144f0"><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt">Source: <a href="https://macvendors.com/">https://macvendors.com/</a><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<p class="MsoNormal">On Tue, May 22, 2018 at 4:30 AM, Ryan Huff <<a href="mailto:ryanhuff@outlook.com" target="_blank">ryanhuff@outlook.com</a>> wrote:<o:p></o:p></p>
<blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in">
<p class="MsoNormal" style="margin-bottom:12.0pt">Yes, that is correct. <br>
<br>
The ports are differentiated by the device name. However, the ports themselves are registered to CCM and communicate on the network through a single network interface on the ATA.<br>
<br>
The second port in the ATA will have the first two characters striped from the beginning of the MAC address and a “01” appended at the end of the MAC address (shown in the device name of the two ports).<br>
<br>
Essentially, the ATA is a mini, purpose built media conversion switch. A lot going on under the hood of those silly little things when you think about it :).<br>
<br>
Thanks,<br>
<br>
Ryan<br>
<br>
> On May 22, 2018, at 04:57, Jon Fox <<a href="mailto:jonfoxipt@gmail.com">jonfoxipt@gmail.com</a>> wrote:<br>
> <br>
> Hello All<br>
> <br>
> Trying to troubleshoot an issue with a Cisco ATA - CUCM 10.5.2SU3<br>
> <br>
> I've not had to touch these for some time, so cannot remember if its natural behaviour for Port 1 and Port 2 registering with the same IP address? Is that standard? - Screenshot attached.<br>
> <br>
> <image.png><br>
> <br>
> <br>
> Many thanks<br>
> Jon<br>
> _______________________________________________<br>
> cisco-voip mailing list<br>
> <a href="mailto:cisco-voip@puck.nether.net">cisco-voip@puck.nether.net</a><br>
> <a href="https://puck.nether.net/mailman/listinfo/cisco-voip" target="_blank">https://puck.nether.net/mailman/listinfo/cisco-voip</a><br>
<br>
_______________________________________________<br>
cisco-voip mailing list<br>
<a href="mailto:cisco-voip@puck.nether.net">cisco-voip@puck.nether.net</a><br>
<a href="https://puck.nether.net/mailman/listinfo/cisco-voip" target="_blank">https://puck.nether.net/mailman/listinfo/cisco-voip</a><o:p></o:p></p>
</blockquote>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</body>
</html>