Hmm, that’s interesting thanks Mark… when connecting to a Firebird 3.0.1 server, I see this in mon$attachments (where mon$system_flag=0):

MON$REMOTE_PID MON$REMOTE_PROCESS        MON$REMOTE_PROTOCOL MON$REMOTE_VERSION

-------------- ------------------        ------------------- ------------------

<null>         <null>                    TCPv4               P10

23184          C:\Apps\fbclient\isql.exe TCPv4               P14

But when connecting to Firebird 3.0.2 (or 3.0.3 nightly… sorry about the confusion with version numbers there!) I see:

MON$REMOTE_PID MON$REMOTE_PROCESS        MON$REMOTE_PROTOCOL MON$REMOTE_VERSION

-------------- ------------------        ------------------- ------------------

<null>         <null>                    TCPv4               P14

19512          C:\Apps\fbclient\isql.exe TCPv4               P14

In each case the monitoring attachment is made using a Firebird client while an existing idle connection from InterBase 7.5.1 isql is open.  Firebird 3.0.1 reports the InterBase client as using protocol version 10, but Firebird 3.0.2 reports it as protocol version 14.