I'm currently running the latest openwrt 23.2 locally on a linksys wrt3200acm (no permanent wan connections) with an ubuntu SSH server on one lan port and a [windows] client on the 2nd lan port. The ubuntu SSH server is active and uses SSH key authentication with the router being the only authorized device that has the key. I can successfully get root access to the Ubuntu SSH server from the router by typing
ssh -i /root/.ssh/ubuntukey 192.168.4.229 -p 2229
My question is how can I forward this now authorized SSH session from the router to be accessible from another SSH client on the LAN? The main 2 restrictions being the SSH client on the LAN won't have the ubuntu server SSH key or IP as well as not having the router password (but the routers authorized SSH connection to the ubuntu server will already be manually activated by me) and the client will have to go through the router using something like ssh root@192.168.4.1:2230 to access the active forwarded ubuntu SSH session.
I'm guessing some sort of netcat,ncat,cryptcat,socat tool will help me but the versions and variations are different here as i found out from [SOLVED] Nc listening to local port. My latest attempt was trying
ssh -i /root/.ssh/ubuntukey 192.168.4.229 -p 2229 | ncat -l -p 2230
but I get a response of SSH-2.0-PuTTY_Release_0.80 when I try to use my SSH client on windows.