Internal SIP Extensions

With the latest version of FreePBX do you still nedd to install BIND to let internal extension work when you have no internet?

The FreePBX version is irrelevant. The solution you want is in Asterisk 12 but you have to use PJSIP, nothing can be chan_sip

Well, I am using the latest version, and I can use it no problem without the internet. Do your phones use a domain name for the server? e.g. If you use all IP like me, it should work just fine.

All IP works fine. It’s when you have a domain name in any of the trunk settings if using chan_sip