The DNS behavior on SPA 9XX - How it works? Dynamic or static after reboot?

Unanswered Question
Dec 7th, 2009

Hi,

First I would like to describe my installation to have the guideline to my problem.

I am supporting an Asterisk Installation running with minimum problem for the last 2 years. We have 2 companies connected by IAX with a total amount of 80 users, 10 users are allocated outside of the HQ, they work in small offices that have the SPA 942, SPA 922 and SPA 962.

These users are connect to the HQ of the company.

In the last 18 months all the 10 remote users were working ok with no problem at all, we were using an static IP.

Because of commercial issues with the internet provider I was forced to work with a new one that at the moment is offering a connection Optics Fiber with 100mb/20mb connection.

In the present the service is not able to have a static IP, so I made a account in Dyndns and with the dynamic pointer made by the router I am supporting 3 VPN'S, 1 MS Exchange, 1 game platform, 1 asterisk, FTP and http page for intranet and CRM.

The connection IP on the 10 remote SPA are also pointing to the Dynamic DNS and they run ok in the first Boot.

Now the problem, or better the Question:

The ISP connection renewing the public IP in 72H, in this case we may have a period of time that the SPA will try to re-connect to the dynamic DNS with no success of course.


This is the problem, after the reconnection of the ISP service with the update of the dynamic DNS the SPA will not be able to resolve the new IP address.
The key line will be yellow (amber) and it will not be possible to the SPA resolve the new IP, it appears that the SPA is blocked with the old IP and it is not possible to clear is memory.

Only after a new restart, or a new boot the SPA will resolve the new Dynamic IP and it will work fine immediately.

Please keep present that when we have the new reconnection of the new IP the others services will be working ok, it isn´t a problem of updating the dymanic IP, it's a problem of resolving the new dynamic IP in the SPA.

So, how is working the DNS in the SPA 9xx models?

- is it updated only at the first boot?

- doe it allow to work like " a real" dns service?

- why I only loose the register service and the others key assign to "extensions" are able to refesh the new IP? SPA 942 and SPA 962?

Please fell free to pm me in order to have some more details.

All the SPA are running the last firmaware available 6.1.5a

http://img140.imageshack.us/img140/9198/spa007.jpg
http://img443.imageshack.us/img443/8533/spa001.jpg
http://img181.imageshack.us/img181/4350/spa004.jpg

Please advice when possible, I need to solve this problem and one of the alternatives is to replce the SPA of these 10 users by other IP telephone.

Beste regards

I have this problem too.
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TridonicAtco Wed, 12/09/2009 - 02:15

Hi.

I am sorry but did I made something wrong?

let me see, I have in mine company 80 SPA that represents around 10.000€ plus SPA 931 and PAP2P and after 2 days work time nobody from Forum support was able to write a small sentence about my question?

Is my question incorrect? or does it show that I am performing something illegal?

Sometimes is hard to understand the behaviour of big companies, as big they are as far they are from the clients.

Just learning my lesson!

Regards

Alberto Montilla Wed, 12/09/2009 - 02:56

Dear Sir;

Thanks for highlighting your issue. If your issue is time bounded, I would suggest you contact the Small Business Support Center, they will be able to follow up your case in a timely manner. The support community, although usually gets responded very fast, has no time committments, so depending on people's availability your response may be delayed (like your case - not usual but may happen).

The Small Business Support Center contact details are here: http://www.cisco.com/en/US/support/tsd_cisco_small_business_support_center_contacts.html

Now for the case. Could you please capture the network traces, to see the initial DNS query/response and the initial register? We would like to understand better the issue (see what the SPA phone is receiving on the DNS Query response and the 200 OK message as register reply at the initial and then on the failure condition).

Regards, and I appreciate your patience.
Alberto

TridonicAtco Wed, 12/09/2009 - 03:37

Dear Alberto,

Many thanks for your reply.

I don´t have a time limit to solve my problem but I need to inform my supervisors about the next steps to do, we have been for the last 4 months to solve by ourselves this issue and finnaly we realize that the task is behind our knowledge's.

The post that I made a few hours ago was a way to express my disappointment facing the scenario that I was afraid to append, I don´t think that pressing is a way to have a reply, but I must tell you that at this moment I am really more confidante, at least I can inform our next steps and win some more time to solve this issue, that in the last situation will be to replace the SPA units with a different manufacture, something that I don´t want to append!!!

Regarding your request

Could you please capture the network traces, to see the initial DNS query/response and the initial register? We would like to understand better the issue (see what the SPA phone is receiving on the DNS Query response and the 200 OK message as register reply at the initial and then on the failure condition).

Please help me to understand:

Should I made a syslog report with the log of the SPA in the "malfunction" period, this means that I will install the syslog server, collected the data after the initial boot ( running ok) and them wait 3 days to have the IP renew and collect the "problematic" logs event?

If yes I will drive to one of our remotes sites and install the syslog in a "demo telephone unit) to have a clean log with initial and final history.

Or do you want to have the full network protocol anylasied with wireshark to "see" the network activity between the SPA and the possible DNS request?

Many thanks for your help and advice.

Alberto Montilla Mon, 12/14/2009 - 07:26

Dear Sir;

Please see below.

TridonicAtco wrote:

Dear Alberto,

Many thanks for your reply.

I don´t have a time limit to solve my problem but I need to inform my supervisors about the next steps to do, we have been for the last 4 months to solve by ourselves this issue and finnaly we realize that the task is behind our knowledge's.

The post that I made a few hours ago was a way to express my disappointment facing the scenario that I was afraid to append, I don´t think that pressing is a way to have a reply, but I must tell you that at this moment I am really more confidante, at least I can inform our next steps and win some more time to solve this issue, that in the last situation will be to replace the SPA units with a different manufacture, something that I don´t want to append!!!

Regarding your request

Could you please capture the network traces, to see the initial DNS query/response and the initial register? We would like to understand better the issue (see what the SPA phone is receiving on the DNS Query response and the 200 OK message as register reply at the initial and then on the failure condition).

Please help me to understand:

Should I made a syslog report with the log of the SPA in the "malfunction" period, this means that I will install the syslog server, collected the data after the initial boot ( running ok) and them wait 3 days to have the IP renew and collect the "problematic" logs event?

If yes I will drive to one of our remotes sites and install the syslog in a "demo telephone unit) to have a clean log with initial and final history.

Or do you want to have the full network protocol anylasied with wireshark to "see" the network activity between the SPA and the possible DNS request?

[Alberto] Yes. I prefer the network traces. If you have the syslog this would also help.

Many thanks for your help and advice.

TridonicAtco Mon, 12/14/2009 - 07:49

Dear Alberto,

I will arrange the installation of one of our remote SPA in order to have the syslog and network trace to study the behaviour of the unit.

this will however take 1 to 2 weeks to have the log.

Alberto I will send to you a PM, please read it when possible to you.

thanks