Using the TCP transport

Unlike RAET, which uses a different type of keys, the TCP transport uses the same keys as the ZeroMQ transport. This means that you can switch from ZeroMQ to TCP and back as you wish, bearing in mind that the master and minions must also be restarted to pick up the change.

Both master and minion use the same setting to switch to the TCP transport:

transport: tcp 

However, as of the Carbon release of Salt, minions may instead be configured to use a setting of detect:

transport: detect 

When a minion is configured this way, it will check with the master while starting up to see which transport it is configured to use. It will first check to see whether the master is configured to use zeromq. If it can't connect that way, then it will attempt to connect using tcp. If that also fails, then the minion will behave as if the master is unavailable.

Whether you expect to use tcp in the future or stick with zeromq, I recommend you give the detect option a trial run and keep it...