How does one confirm that JNLP4 is being used? I tried the latest Jenkins ver. 2.38 (weekly) and configured a JNLP slave (there's no option to configure what kind of JNLP slave).
Additionally, the agent logs don't show much in the way of output confirming which JNLP protocol is even being used. Here's the full log output from the initialization of the JNLP slave.
JNLP agent connected from /REDACTED
<===[JENKINS REMOTING CAPACITY]===>Slave.jar version: 3.3
This is a Unix agent
Agent successfully connected and online
So far, I'm not sure how to tell what protocol is being used.