Trunks with Asterisk+FreePBX

I am having an issue with my trunks.
I am using FreePBX to configure a SIP trunk line. I am using Axvoice as the SIP provider. When I enter the configuration details and apply them, suddenly my extensions cannot dial. It is also not registering with the provider. Can Asterisk get stuck trying to connect to the SIP trunk and prevent all the extensions from working?

As soon as I delete the trunk, everything works fine again.
Not sure at this point.

You probably have a broken DNS configuration.

A broken DNS in regards to the SIP registration? Or how the phones go offline in the presence of a trunk?

Yes.

A broken DNS configuration will cause Asterisk to stall waiting for responses that never arrive, in critical parts of the SIP processing.