Trying to proxy tcp traffic through a distant server

natsch

12/21/23, 6:11 PM

During the past few days I tried a few things to make my VPS proxy tcp traffic (depending on port) to my home server (both ubuntu servers).

Client <------> VPS <------> Home server

To be more specific, I've got a home server running some apps that I want to be hidden behind my VPS (not on the same subnet) and I want source ip to be preserved when a client tries to reach an app on my home server.

Currently I'm running NGinx streams as a reverse proxy. It works pretty well but client ip is lost (replaced by my VPS ip). There is on option to keep it proxy_bind $remote_addr transparent; but it would require my home server to output traffic to my VPS like a gateway (and I do not have a solution for this without having both of them on the same network).

I tried using SSH Port Forwarding but source ip is also lost (replaced by my home server local ip). I also tried IP Gre tunneling (Didn't make it at the end...)...

The best for me would be that my VPS and my home server are connected through a tunnel, I think ?

Client <------> ( VPS <-tunneled-> Home server )

But as I said, all I need is to send VPS port specific traffic to my home server with source ip preserved and my VPS ip as server ip.

Hope someone will have a solution !

Have a great day !

153

1 + 2

ubuntu

nginx

proxy

tcp

Tero Kilkanen

12/21/23, 9:47 PM

It is not possible without support from the application protocol.

natsch

12/22/23, 5:59 AM

I have multiple apps but the most important is a docker mail server instance. For mailing it's easy to impersonate my VPS using a relay but in the other way I need the source ip. Does-it help ?

Score:0

Server

natsch

12/27/23, 6:14 AM

Finally, I gave up finding a generic solution and used HAProxy in combination with Postfix and Dovecot. See https://www.linuxbabe.com/mail-server/smtp-imap-proxy-with-haproxy-debian-ubuntu-centos

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Elon Musk

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