How do I use autossh to set up a no-frills socks proxy?

Question

I use ssh -D 12345 [email protected] to set up dynamic port forwarding via host somewhere.com. I want to switch to using autossh to daemonize the thing and to make sure I don't need to manually monitor it.

I installed the autossh package (on my Linux Mint 18.1), but I don't quite understand what I'm supposed to do. Why aren't there any configuration/defaults files under /etc/? Where's the service which starts autossh tunnles? Do I need to do all of that manually?

Manual page for [`autossh`](https://linux.die.net/man/1/autossh) should explain you everything. — Jakuje, Jan 26 '17 at 12:17
@Jakuje: Very much unlikely, as it cannot tell me about distribution-level facilities for using autossh, such as init.d scripts / systemd services, `/etc/defaults/` files and so on. — einpoklum, Jan 27 '17 at 08:04
... indeed, the man does not even begin to answer my question. — einpoklum, Jan 27 '17 at 08:05
No, there is no such service. If you wouls wqnt one, you need to write one. — Jakuje, Jan 27 '17 at 08:26

score 4 · Answer 1 · edited Mar 27 '20 at 02:18

Explanation for fingerpich's answer:

autossh -f causes autossh to drop to the background before running ssh.
-M specifies a monitoring port for autossh to use.
-D specifies the local socks proxy port
-N specifies do not execute a remote command. this is useful for just forwarding ports

If you don't want to use a monitoring port the following command instead uses SSH keep-alives every 10 seconds to detect failure:

autossh -f -M 0 -o "ServerAliveInterval 10" -o "ServerAliveCountMax 3" -D localhost:1234 -N [email protected]

score 2 · Answer 2 · answered Jan 21 '20 at 14:40

2

I found the answer here and used the following command

autossh -f -M 5731 -D localhost:1234 -N user@ip

answered Jan 21 '20 at 14:40

fingerpich

121
4

Can you explain why this combination of switches is what we should use, and what exactly this will do? – einpoklum Jan 21 '20 at 15:40
You can find them using `man ssh` and `man autossh`. I used it to make a reliable socks proxy – fingerpich Jan 21 '20 at 21:23
1

On SE websites, answers should be mostly self-contained and not essentially references. I can, indeed, find them, but the answer should be expanded nonetheless. – einpoklum Jan 21 '20 at 22:11
thanks, but I just tried to share a solution – fingerpich Jan 21 '20 at 22:30

How do I use autossh to set up a no-frills socks proxy?

2 Answers2