How to make ssh work from termux on android to a sshd server (PC) ?

[SynapseScribe]

I tried various combinations of "block connections without VPN: off" & "Do not route Private IPs = on" & ISOLATE/BYPASS/ALLOW/EXCLUDE firewall rules for termux, but nothing seems to work. Any idea? thanks

[SynapseScribe]

Anyone managed to make ssh work from phone to pc?

[luckmagnet]

Why do you want it on phone?

[SynapseScribe]

not sure how this is relevant, but the use case is to remotely manage my hosts from phone in the lan (eg i have servers running in headless mode)

[ignoramous]

Don't think we've tested Rethink in any of these P2P & LAN scenarios. We've implemented Configure -> Network -> Endpoint-Independent Mapping in v055o and above as it may help P2P apps, but it doesn't look like it has. There's also Configure -> Network -> Change Interface IPs in yet-to-be-released v055v (may be we'll change the label to something else before release), which some claim, if set to match the underlying network's interface IPs (the underlying networks are mostly Wifi and/or Mobile on Android smartphones), makes these apps that need P2P / LAN connectivity work.

See also:

• How to make KDE Connect work? #2653

(and many other open issues and discussions on "LocalSend" / "Termux" / "Chromecast" / "KDE Connect" etc).

[SynapseScribe]

can you please summarize, what i need to enable/disable to make it work ? i am really confused rn

[ignoramous]

Turning ON Configure -> Network -> Endpoint-Independent Mapping available only on v055o and above.

Folks have reported that it had made no difference to apps like LocalSend and KDE Connect (I imagine, it won't help with SSH either).

---

Setting Configure -> Network -> Change Interface IPs in yet-to-be-released v055v (in lieu of v055v, you can try 27 May Alpha release, which can be installed side-by-side with regular Rethink flavours).

Some claim, if Rethink's interface IPs are set to match the underlying network's interface IPs (the underlying networks are mostly Wifi and/or Mobile on Android smartphones), makes these apps that need P2P / LAN connectivity work.

[SynapseScribe]

ok i installed alfa version 10b21e7

Turned ON Configure -> Network -> Endpoint-Independent Mapping
Setting Configure -> Network -> Custom Interface IPs for VPN ---> changed to manual to match my wifi lan:
gateway: 192.168.1.201/24
router: 192.168.1.202/32
dns: 192.168.1.203/32

PC IP: 192.168.1.100 (/24 ; gw physical router is 192.168.1.1)
phone IP: 192.168.1.200 (on wifi, same physical router)

from phone (termux) i tried ssh -vvv myuser@192.168.1.100, it still fails with connection reset

[ignoramous]

Thanks for testing this. If you're technically savvy enough, may be you find something in "packet captures" (Configure -> Settings -> Packet Capture) to help debug this issue (you can redirect the capture to either Android's Logcat, in which case you'd have to retrieve the stream at the same time as the app is running via adb logcat command grepping for GoLog or snooper.go; or, to a separate file in the publicly accessible Downloads folder, which can be later opened with any file viewer). Not a big deal if you can't do so.

[SynapseScribe]

what else should i do?
how should "block connections without VPN" & "Do not route Private IPs" , ISOLATE/BYPASS/ALLOW/EXCLUDE be set?

[ignoramous]

You don't have to do anything. We'll eventually get to debugging why SSH in Termux fails (and other apps like KDE Connect / LocalSend). For now, the only workaround if you do not have "Block connections without VPN" turned on is:

1. "Exclude" Termux (and other such apps that don't behave nicely behind Rethink's firewall / NAT), or
2. Turn ON Configure -> Network -> Do not route Private IPs.

[SynapseScribe]

For now I prefer to have the "block connections without VPN" turned on to prevent leaks and i intend to keep it this way. Thank you for the awesome app !