connections(images) - phpMan

doveadm-proxy (1)    - Handle Dovecot proxy connections (obsolete)
DTLSv1_listen (3ssl) - Statelessly listen for incoming connections
ftpcount (1)         - show current number of connections for each proftpd se...
ftptop (1)           - display running status on proftpd server connections
listen (2)           - listen for connections on a socket
listen (3p)          - listen for socket connections and limit the queue of i...
nc (1)               - arbitrary TCP and UDP connections and listens
netcat (1)           - arbitrary TCP and UDP connections and listens
netstat (8)          - Print network connections, routing tables, interface s...
SSL_CTX_get_info_callback (3ssl) - handle information callback for SSL connec...
SSL_CTX_set_info_callback (3ssl) - handle information callback for SSL connec...
SSL_get_info_callback (3ssl) - handle information callback for SSL connections
SSL_set_info_callback (3ssl) - handle information callback for SSL connections
SSL_stateless (3ssl) - Statelessly listen for incoming connections
ssltap (1)           - Tap into SSL connections and display the data going by