Rsync through router without router config

grant123 · Veteran Joined: 23 Mar 2005 Posts: 1080

Can I rsync to a system that is behind a router without configuring the router? Maybe if I have the system I want to rsync to make itself available to me somehow?

Hu · Moderator Joined: 06 Mar 2007 Posts: 21607

You can use as an rsync server any machine to which you can connect over an rsync transport. Typical consumer routers will by default drop connection requests coming from the Internet.

grant123 · Veteran Joined: 23 Mar 2005 Posts: 1080

I'm giving a laptop to a non-technical person and I want to be able to rsync to it periodically. I could try to explain to them how to configure their router but I'm wondering if there is a way around that. Any creative solutions? Can I have the laptop connect to a server on the internet which will hand off the rsync connection for me?

UberLord · Posted: Wed Jan 20, 2016 9:58 pm Post subject:

Sounds like you need a VPN.open VPN is quite good for this.
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grant123 · Veteran Joined: 23 Mar 2005 Posts: 1080

Thanks Uberlord. It seems like OpenVPN would be a lot of trouble for this. Any other options?

UberLord · Posted: Thu Jan 21, 2016 4:08 am Post subject:

OpenVPN is quite easy to configure at both ends. And is pretty much guaranteed to work.
Of course, you could employ another brand of VPN.

The other option, as you say, is configuring their router.
This has it's own set of problems
* Can the router port forward to start with?
* What if someone else wants the port (a rsync server belongs to spouse?)
* Do it again when router is swapped out
* Do it again if laptop moves out
* Laptop could be on business trips a lot - i don't know if you need to rsync at these times.

I'm sure there are more reasons, but frankly installing some kind of VPN end point is your best option for less hassle later.
_________________
Use dhcpcd for all your automated network configuration needs
Use dhcpcd-ui (GTK+/Qt) as your System Tray Network tool

Ant P. · Watchman Joined: 18 Apr 2009 Posts: 6920

IPv6 would be a good option - but if you're stuck with the kind of router that causes this problem, it probably doesn't support that at all.

UberLord · Posted: Thu Jan 21, 2016 11:49 am Post subject:

krinn · Watchman Joined: 02 May 2003 Posts: 7470

you may also just tunnel rsync with ssh, and then just need a valid ssh access already set behind your router.

steveL · Posted: Thu Jan 21, 2016 12:37 pm Post subject:

Yeah rsync over ssh is lovely; we use it on the LAN as well, in addition to ssh-fs for things like distfiles.

#openssh is the best place to get incisive advice from professionals using it, ime.
Though you'd also get a good deal of help on rsync in #bash

Both on IRC: chat.freenode.net or .org

UberLord · Posted: Thu Jan 21, 2016 1:12 pm Post subject:

Surely rsync over ssh tunnel requires the *same* router modifications as the rsync straight to the laptop - the router needs to port forward to the laptop.
The problems with this approach I listed above and still apply.
Unless I'm missing something mind-numbingly obvious...
_________________
Use dhcpcd for all your automated network configuration needs
Use dhcpcd-ui (GTK+/Qt) as your System Tray Network tool

grant123 · Veteran Joined: 23 Mar 2005 Posts: 1080

Could I have the laptop automatically connect to my server via SSH after prompting the desktop user for credentials? Then the SSH connection would be up all the time and I could rsync to the laptop that way.

szatox · Advocate Joined: 27 Aug 2013 Posts: 3131

UberLord · Posted: Thu Jan 21, 2016 5:54 pm Post subject:

steveL · Posted: Thu Jan 21, 2016 9:41 pm Post subject:

grant123 · Veteran Joined: 23 Mar 2005 Posts: 1080

The way my maintenance script works, I need to be able to rsync push to the laptop. Can I have SSH automatically connect so I can rsync push through that connection to the laptop, but for security not give the laptop a real shell on the system it's connecting to?

1clue · Advocate Joined: 05 Feb 2006 Posts: 2569

You could add a point for your rsync, so there's something outside the firewall. Something that works like dropbox.com.

grant123 · Veteran Joined: 23 Mar 2005 Posts: 1080

1clue, yes, what is available like that?

1clue · Advocate Joined: 05 Feb 2006 Posts: 2569

you could use any cloud storage and rsync, or you could use dropbox. Dropbox for Linux is basically a web page, not sure I'd recommend that for what you're talking about.

You could also go get a minimal box on linode.com for example, and do a true rsync since that's a linux box.

Sorry I don't have a lot of solutions for you, I've never needed to do this sort of thing.

Come to think of it though, what sort of files are you talking about? Have you considered a git repository?

Personally my solution would be to install that vpn. You didn't like that, I'm just trying to figure out something else that might work.

Disclaimer: I am very suspicious of cloud storage, especially any service you get for free. If you get a service for free on the Internet, you are not the customer. You're the product.

krinn · Watchman Joined: 02 May 2003 Posts: 7470

1clue · Advocate Joined: 05 Feb 2006 Posts: 2569

Laptops being notoriously off and on all the time, an rsync would make more sense if it were initiated from the laptop anyway.