can I do ssh port forwarding after I've already logged in with ssh?

I have an Ubuntu server example.com and I have ssh'ed into it. But only after I ssh into it, do I realize that I meant to do ssh -L 8000:localhost:9000 example.com. Is there a way to create that tunnel in an already establi开发者_开发技巧shed and running ssh connection?

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If you set your escape character with EscapeChar option in ~/.ssh/config or with the -e option you can.

Assuming an escape of ~: ~C-L 8000:localhost:90000 will do it.