[asterisk-users] Polycom SIP Phones On LAN can't register without WAN (Internet) Access

[Eric "ManxPower" Wieling]

Noah Miller wrote:
> Hi Shawn -
> 
>> We have several Polycom 500/501/601's on both a LAN and at employee 
>> homes.
>> The problem we are having is if our internet connection goes down the 
>> Local
>> LAN phones loose their connection to the Asterisk Server.
>> I've checked everything I can think of but can't figure out why its
>> happening.
>> I believe since the Asterisk Box is on the LAN and the phones are on the
>> same LAN then it shouldn't need internet to function.
>>
>> The closest I have narrowed this down is to the DNS area. I found that 
>> if I
>> block access to our ISP's DNS that the phones aren't able to register 
>> with
>> asterisk.
>>
>> This baffles me because the phone has the LAN address for the Asterisk
>> server so I don't know why it's doing DNS lookups.
> 
> Hmm.  Well, you've got me.  I don't know why it would be doing that,
> it certainly shouldn't be.  You might try a newer version of the SIP
> firmware or the 3.2.2 bootrom.
> 
> If it still happens with the latest bootrom/firmware, you could do a
> packet trace on the phone.  Is it doing DNS queries?  If so, I'd call
> your Polycom reseller and have them take this up with Polycom (support
> requests are supposed to go through the reseller).  Actually, in any
> case, I'd take it up with your Polycom reseller.

Asterisk tends to get very upset when DNS is down.

Make sure you have NO hostnames in any of your Asterisk config files. 
Also make sure that all interfaces on the Asterisk box are correctly 
listed in /etc/hosts