ssh to a server behind NAT without VPS being the bridge during communication

TWTom

7/30/24, 10:38 AM

I currently can ssh through my localhost behind NAT using VPS as reverse SSH server.

ssh -f -N -R 1234:localhost:22 user@[vps_ip]

And I can do the following to connect to my localhost SSH server from other place:

ssh my_user@[vps_ip] -p 1234

My problem is that this connection will have high latency because the VPS is in the US (only free in the US) and I'm in East Asia. Is there a possible way that can start a script automatically after connection, and do some tricky stuff (to punch a TCP hole maybe) to set a SSH communication directly from anywhere to my localhost to reduce latency? I want it to make the client side only have to do ssh my_user@[vps_ip] -p 1234 to connect to my localhost.

0 + 4

ssh-tunnel

A.B

7/30/24, 1:04 PM

I'm not sure the question fits here, but anyway, to punch a hole, you need at least one side of the two clients to have adequate network properties, if not both. For example if the two clients are behind CG-NAT, no punching (whatever help is available from the server to try and achieve it).

TWTom

7/30/24, 3:14 PM

Thanks for the answer, @A.B Do you mean if both the client and the localhost server is behind NAT, direct communication is not possible if I don't want the client side has any additional configurations?

A.B

7/30/24, 4:19 PM

I won't continue beyond this comment: I wrote "[CG-NAT](https://en.wikipedia.org/wiki/Carrier-grade_NAT)", not just NAT. There are different types of [NAT](https://en.wikipedia.org/wiki/Network_address_translation#Methods_of_translation). Those with interesting network properties can get to punch holes, with the help of a 3rd party. An example 3rd party help is a [STUN server](https://en.wikipedia.org/wiki/STUN). SSH won't help much in this regard.

Jaromanda X

7/31/24, 1:52 AM

if you're afflicted by CG-NAT you can use something like tailscale (or the self hosted version headscale) - there are many other variations that essentially use wireguard under the hood to provide secure and fast end-to-end connections - you can install them on your VPS, but don't worry, the "server" component is just there to establish direct connections

Elon Musk

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EN: ssh to a server behind NAT without VPS being the bridge during communication

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