How to check is connection encrypted

Hi!


Old Postgres

"PostgreSQL 9.1.2 on x86_64-unknown-linux-gnu, compiled by gcc-4.4.real 
(Debian 4.4.5-8) 4.4.5, 64-bit"

Server has symlinks server.crt and server.key in data directory 
/var/lib/postgresql/9.1./main and ssl=true in postgresql.conf file.

Server is running in old Debian squueze.

Client accesses server from Windows 10 using psqlODBC driver with 
sslmode=allow in connection string.

How to verify that connection is encrypted ? Is there some command in client 
or server or can some protocol analyzer used if no easier way?

Andrus.

Posted also in 
https://stackoverflow.com/questions/55296044/how-to-check-is-connection-encrypted