Recent Change To Determining 3CX SBC Local IP Address?

[uptime1]

One of our 3CX systems v18 U5 has been running well for over four years. But, in the past two weeks, at one location, the only phone behind the RPi 3CX SBC v18.1.36 (Stretch, apt full-upgrade) is pushed the RPI's External NIC IP address for Outgoing Proxy, instead of, correctly, the RPI's LAN IP address, which is the interface to which the phone is connected.

Curiously, none of the other phones/SBC's, all with same version, at other locations, have this problem - yet. And, this problem wasn't a problem until about two weeks ago. No human has made any changes to the system in months.

But, has something recently changed with how the RPi 3CXSBC app or 3CX Server figures out the LAN IP Address of the RPi 3CXSBC computer?

As a non-permanent workaround, grudgingly, I temporarily adjusted "LocalSipAddr=" to the actual LAN IP of the RPi, but I definitely want to stay far away from having to individually modify 3cxsbc.conf across a large swath of SBC's, especially given their limited remote mgmt access.

On a related note, for troubleshooting, I wanted to experiment with an older 3cxsbc app version, but "apt install 3cxsbc version=16.2.24" failed with error "Unable to locate package version". Is there a way to get at older versions?

Thanks!

 

[JohnS_3CX]

Hi,

If your phone has the site's WAN IP as its SIP proxy, then the SBC has been probably made into thinking that its LAN IP = the WAN IP. It then reports this to 3CX, and in turn this provisions your phone with the WAN IP as its proxy.

The SIP proxy is basically your Pi's LAN IP so the question is why did this happen in the first place? Has someone made any changes to the firewall settings, assigning the WAN IP to the Pi? Or Has someone added any rules on the firewall which would cause this to happen?


Troubleshooting this:
I think you should wipe your Pi, and rebuild it using the files and instructions from here to troubleshoot with a clean installation. Do not install older versions, they are no longer supported and they contain bugs that have been fixed in the latest version. Make sure you are using it Wired, not with WiFi.
https://www.3cx.com/docs/installing-pbx-raspberry-pi/

You can grab a second SD card to do this on if you prefer to not disturb your original one while testing, but I would recommend to keep to the guide and not make any other changes on the Pi or modifications to the config files. When done, you can look at your management console and see what LAN IP the Pi reports. If it is the WAN IP again, check your firewall and see if there are any rules for the IP or MAC of the Pi.

 

[uptime1]

Thanks for your reply. No changes have been made to any phone, network or SBC devices at any of the over 10 locations for many years. I just had a meeting with my techs about this issue because it's affecting one of our most active phone using customers, and they informed me the extension that's having the SBC problems was modified about two weeks ago - a BLF was modified, and during that process, a prompt appeared to re-select the SBC for the phone. Afterwards, the SBC started having problems. And, to add injury to insult, now we're discovering that some outbound calls hang up after first ring or after several rings. Yet, as mentioned in my original post, none of the other remote phones or SBC's have this problem! Although, a new extension, phone and SBC I just added for troubleshooting, is also having the Outbound Gateway IP Address issue and call hang ups (log shows the server is hanging up the call)!! Something is amiss, and it's looking more and more like it's something server software based. HELP!

Oh, I put the errant extension user (the owner of the customer) on the 3CX Android app. They're working well but they want their desk phone to work as it has for years.

 

[ivank]

Could you set the logging level of that SBC to Verbose, restart it, collect the log file and share via PM?