<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Just because the hosts file is present in the OS doesn't mean each different app is going to use it. There are many ways that DNS failures can negatively impact an appliance model UC server.<div><br></div><div>See CSCsw88022 as one example.</div><div><br><div>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: 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>-Ryan</div></span>
</div>
<br><div><div>On Jun 7, 2010, at 10:45 AM, Justin Steinberg wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">there are backup mechanisms built into Cisco UC to handle DNS failures. For example, the appliance CMs maintain their own host files for intercluster communication and does not rely on DNS to communicate between CM nodes.<br>
<br>Additionally, all IP phone models that I have used will fail back to defined TFTP servers (IP addresses) should the phone be unable to communicate with the CM name (DNS hostname) defined in the CM priority list. Depending on your deployment, you either have both your pub/sub defined as TFTP servers or if you have a larger cluster you can define different subs in the TFTP list after a dedicated TFTP server and assign different subs to different DHCP scopes.<br>
<br>DNS is becoming a requirement in UC deployments as more services utilize it. SIP SRV is a good example.<br><br>The official recommendation from Cisco in the SRND does support Tanner's position, though it acknowledges that DNS is a requirement for certain designs.<br>
<br><a href="http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/srnd/8x/netstruc.html#wp1184840">http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/srnd/8x/netstruc.html#wp1184840</a><br><br><br><br><br><div class="gmail_quote">
On Mon, Jun 7, 2010 at 10:29 AM, Jason Aarons (US) <span dir="ltr"><<a href="mailto:jason.aarons@us.didata.com">jason.aarons@us.didata.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
Typically in the enterprise, having dial tone 100% reliant upon external DNS is frowned upon. These are the same places with trading floors with billions of dollars using host files in Unix to ensure they work non-stop. Since DNS is maintained by the server team in the Enterprise your relying on someone else as well.<br>
<br>
Wonder if Verizon or Time Warner Telcom SIP cloud relies on DNS for their underpinnings. Take down Verizon's internal SIP DNS servers and all their customer's go down? Better be a good firewall/server/patched BIND, etc.<br>
<div class="im"><br>
<br>
-----Original Message-----<br>
From: Bill [mailto:<a href="mailto:bill@hitechconnection.net">bill@hitechconnection.net</a>]<br>
Sent: Monday, June 07, 2010 9:34 AM<br>
To: Jason Aarons (US); 'Tanner Ezell'; 'Gates, Jobe R.'<br>
Cc: 'cisco-voip'<br>
</div><div><div></div><div class="h5">Subject: RE: [cisco-voip] UCCX Install won't see Sub in CUCM Cluster<br>
<br>
Those crazy guys who built the internet to use DNS may have had a good idea.<br>
:)<br>
<br>
There is nothing wrong with using DNS in an IPT environment.<br>
<br>
-----Original Message-----<br>
From: <a href="mailto:cisco-voip-bounces@puck.nether.net">cisco-voip-bounces@puck.nether.net</a><br>
[mailto:<a href="mailto:cisco-voip-bounces@puck.nether.net">cisco-voip-bounces@puck.nether.net</a>] On Behalf Of Jason Aarons (US)<br>
Sent: Sunday, June 06, 2010 11:27 PM<br>
To: Tanner Ezell; Gates, Jobe R.<br>
Cc: cisco-voip<br>
Subject: Re: [cisco-voip] UCCX Install won't see Sub in CUCM Cluster<br>
<br>
If you want to run ASA Phony Proxy you need use DNS for NAT. Starting to<br>
wonder about changing best practice to use DNS when DNS has a high uptime.<br>
<br>
-----Original Message-----<br>
From: <a href="mailto:cisco-voip-bounces@puck.nether.net">cisco-voip-bounces@puck.nether.net</a><br>
[mailto:<a href="mailto:cisco-voip-bounces@puck.nether.net">cisco-voip-bounces@puck.nether.net</a>] On Behalf Of Tanner Ezell<br>
Sent: Sunday, June 06, 2010 8:35 PM<br>
To: Gates, Jobe R.<br>
Cc: cisco-voip<br>
Subject: Re: [cisco-voip] UCCX Install won't see Sub in CUCM Cluster<br>
<br>
And when your DNS becomes unavailable so does everything that it<br>
relies on. Replication and communication cease and you're sunk. Best<br>
practice is to ALWAYS use IP addressing.<br>
<br>
On Sun, Jun 6, 2010 at 5:06 PM, Gates, Jobe R. <<a href="mailto:JRGates@burns-wilcox.com">JRGates@burns-wilcox.com</a>><br>
wrote:<br>
> We arn't using IP's, we're using DNS with no problems.<br>
><br>
><br>
> On Jun 6, 2010, at 8:03 PM, "Tanner Ezell" <<a href="mailto:tanner.ezell@gmail.com">tanner.ezell@gmail.com</a>><br>
> wrote:<br>
><br>
>> Why weren't you using IP address in the first place?<br>
>><br>
>> On Sun, Jun 6, 2010 at 4:35 PM, H, Tim <<a href="mailto:TimH@trstone.com">TimH@trstone.com</a>> wrote:<br>
>>> I opened a TAC on this problem. Turned out the two entries for<br>
>>> CUCM Pub and Sub had to be in the hosts file on both UCCX machines.<br>
>>><br>
>>> Thanks,<br>
>>> Tim<br>
>>><br>
>>><br>
>>><br>
>>> -----Original Message-----<br>
>>> From: <a href="mailto:cisco-voip-bounces@puck.nether.net">cisco-voip-bounces@puck.nether.net</a> [mailto:<a href="mailto:cisco-voip-">cisco-voip-</a><br>
>>> <a href="mailto:bounces@puck.nether.net">bounces@puck.nether.net</a>] On Behalf Of H, Tim<br>
>>> Sent: Sunday, June 06, 2010 2:06 AM<br>
>>> To: Tanner Ezell<br>
>>> Cc: cisco-voip<br>
>>> Subject: Re: [cisco-voip] UCCX Install won't see Sub in CUCM Cluster<br>
>>><br>
>>> Yea, it's in there. I made sure that the database is replicating,<br>
>>> and it is with no issues.<br>
>>><br>
>>> Thanks,<br>
>>><br>
>>> Tim<br>
>>><br>
>>><br>
>>> -----Original Message-----<br>
>>> From: Tanner Ezell [mailto:<a href="mailto:tanner.ezell@gmail.com">tanner.ezell@gmail.com</a>]<br>
>>> Sent: Sunday, June 06, 2010 2:01 AM<br>
>>> To: H, Tim<br>
>>> Cc: James Buchanan; cisco-voip<br>
>>> Subject: Re: [cisco-voip] UCCX Install won't see Sub in CUCM Cluster<br>
>>><br>
>>> Does the second server show up under System --> Servers just fine?<br>
>>><br>
>>> This is certainly odd behavior, does the SUB process calls<br>
>>> successfully? Best bet at this point is to open a TAC case.<br>
>>><br>
>>> I'd be curious to know the cause of this when you get it resolved.<br>
>>><br>
>>> On Sat, Jun 5, 2010 at 10:17 PM, H, Tim <<a href="mailto:TimH@trstone.com">TimH@trstone.com</a>> wrote:<br>
>>>> Yes, both sub and pub have the CM service active.<br>
>>>><br>
>>>> Thanks,<br>
>>>><br>
>>>> Tim<br>
>>>><br>
>>>> -----Original Message-----<br>
>>>> From: Tanner Ezell [mailto:<a href="mailto:tanner.ezell@gmail.com">tanner.ezell@gmail.com</a>]<br>
>>>> Sent: Sunday, June 06, 2010 12:59 AM<br>
>>>> To: H, Tim<br>
>>>> Cc: James Buchanan; cisco-voip<br>
>>>> Subject: Re: [cisco-voip] UCCX Install won't see Sub in CUCM Cluster<br>
>>>><br>
>>>> Is the CallManager service active?<br>
>>>><br>
>>>> On Sat, Jun 5, 2010 at 9:56 PM, H, Tim <<a href="mailto:TimH@trstone.com">TimH@trstone.com</a>> wrote:<br>
>>>>> Yes.<br>
>>>>><br>
>>>>><br>
>>>>><br>
>>>>> Thanks,<br>
>>>>><br>
>>>>> Tim<br>
>>>>><br>
>>>>><br>
>>>>><br>
>>>>> From: James Buchanan [mailto:<a href="mailto:jbuchanan@ctiusa.com">jbuchanan@ctiusa.com</a>]<br>
>>>>> Sent: Sunday, June 06, 2010 12:14 AM<br>
>>>>> To: H, Tim; cisco-voip<br>
>>>>> Subject: RE: [cisco-voip] UCCX Install won't see Sub in CUCM<br>
>>>>> Cluster<br>
>>>>><br>
>>>>><br>
>>>>><br>
>>>>> Are those services activated on the Subscriber (CTIManager, AXL)?<br>
>>>>><br>
>>>>><br>
>>>>><br>
>>>>> James Buchanan | Senior Network Engineer | South Region |<br>
>>>>> Presidio Networked<br>
>>>>> Solutions<br>
>>>>> 12 Cadillac Dr, Suite 130, Brentwood, TN 37027 |<br>
<a href="mailto:jbuchanan@presidio.com">jbuchanan@presidio.com</a><br>
>>>>> D: 615-866-5729 | <a href="http://www.presidio.com/" target="_blank">www.presidio.com</a> <<a href="http://www.presidio.com/" target="_blank">http://www.presidio.com</a>><br>
>>>>><br>
>>>>> CCIE #25863, Voice<br>
>>>>><br>
>>>>><br>
>>>>><br>
>>>>> From: <a href="mailto:cisco-voip-bounces@puck.nether.net">cisco-voip-bounces@puck.nether.net</a><br>
>>>>> [mailto:<a href="mailto:cisco-voip-bounces@puck.nether.net">cisco-voip-bounces@puck.nether.net</a>] On Behalf Of H, Tim<br>
>>>>> Sent: Saturday, June 05, 2010 9:44 PM<br>
>>>>> To: cisco-voip<br>
>>>>> Subject: [cisco-voip] UCCX Install won't see Sub in CUCM Cluster<br>
>>>>><br>
>>>>><br>
>>>>><br>
>>>>> I'm in the middle of doing a new deployment of UCCX and during<br>
>>>>> the install I<br>
>>>>> put in the IP of the CUCM Pub which it sees, but it won't by<br>
>>>>> default bring<br>
>>>>> in the SUB IP with it while doing AXLservice and CTImanager service<br>
>>>>> activations. The CUCM is clustered with good database replication.<br>
>>>>><br>
>>>>><br>
>>>>><br>
>>>>> Any good ideas?<br>
>>>>><br>
>>>>><br>
>>>>><br>
>>>>> Thanks,<br>
>>>>><br>
>>>>> Tim<br>
>>>>><br>
>>>>><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><br>
>>>>><br>
>>>>><br>
>>>><br>
>>>><br>
>>>><br>
>>>> --<br>
>>>> Cheers,<br>
>>>><br>
>>>> Tanner Ezell<br>
>>>><br>
>>><br>
>>><br>
>>><br>
>>> --<br>
>>> Cheers,<br>
>>><br>
>>> Tanner Ezell<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><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><br>
>>><br>
>><br>
>><br>
>><br>
>> --<br>
>> Cheers,<br>
>><br>
>> Tanner Ezell<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><br>
><br>
<br>
<br>
<br>
--<br>
Cheers,<br>
<br>
Tanner Ezell<br>
<br>
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