ssh reverse tunnel into bastion

ssh-reverse-tunnel-bastion

ssh -t bastion -L localhost:port:remotehost:port
use jconsole, visualvm, zmc, etc.

-L [bind_address:]port:host:hostport
     -L [bind_address:]port:remote_socket
     -L local_socket:host:hostport
     -L local_socket:remote_socket
             Specifies that connections to the given TCP port or Unix socket on the local (client) host are to be forwarded to the given host and port, or Unix
             socket, on the remote side.  This works by allocating a socket to listen to either a TCP port on the local side, optionally bound to the specified
             bind_address, or to a Unix socket.  Whenever a connection is made to the local port or socket, the connection is forwarded over the secure channel,
             and a connection is made to either host port hostport, or the Unix socket remote_socket, from the remote machine.

             Port forwardings can also be specified in the configuration file.  Only the superuser can forward privileged ports.  IPv6 addresses can be specified
             by enclosing the address in square brackets.

             By default, the local port is bound in accordance with the GatewayPorts setting.  However, an explicit bind_address may be used to bind the connec-
             tion to a specific address.  The bind_address of ``localhost'' indicates that the listening port be bound for local use only, while an empty address
             or `*' indicates that the port should be available from all interfaces.