ssh port forwarding, netcat test not working

Question

I have two machines, laptop and oracle.

This is a session:

TERMINAL 1 (starts a.netcat on remote machine)

Laptop $ ssh -p 6789  zx@$ORCL_H -i ~/.ssh/identities/oracle/nixos/zx.priv.key  

Oracle $ nc -l 7777

TERMINAL 2 (starts a remote port forwarding)

Laptop $ ssh -p 6789 -L 9999:$ORCL_H:7777 zx@$ORCL_H -i ~/.ssh/identities/oracle/nixos/zx.priv.key

TERMINAL 3 (tries to connect to.netcat server but via local port on laptop)

Laptop $ nc localhost 9999 

--

ORCL_H is set correctly in both T1 and T2

However, when I try to type something in either.netcat sessions, I see nothing. What am I doing wrong?

I've turned GatewayPorts yes on the remote machine.

I should note that the exact sequence of command but with another host (not oracle) works as expected

Answer 1

Check if you do have AllowTcpForwarding yes in your sshd config in the Oracle machine.

EDIT: It should not be able caused by packets silently dropped by firewall as incorrectly suggested in this post before. If you are able to connect there by SSH, the forwarded traffic should be indistinguishable.