Rsync over VPN with specified network interface

[macj72x]

I'm trying to rsync some data to a remote device. I have a vpn server set up on the remote device(192.168.1.2) with my router as the client device. With the local device I have a specific network interface (br1/192.168.5.1) that data needs to travel out of to be routed over the tunnel. I can ping the remote device from the local device using

ping -I br1 192.168.1.2

So is there a certain syntax I need to accomplish this properly or should I look at a completely different architecture? Right now I'm trying different variations of something like this

rsync -avz -e -b 192.168.5.2 /path/to/origin/file/ destusername@192.168.1.2:/path/to/origin/file/

[TheFu]

Check the routing tables before and after the VPN is up. Ensure the tunnel routing metric is lower than non-tunnel metrics for the route desired.

There isn't any way to force an application to use a specific route/VPN except by controlling the routing tables on the system. Here's a handy alias:

alias iproute='ip route | column -t'

since route -n is deprecated and has been using unsupported code since 2011! The newer ip commands have the same information, just in an ugly format. Sigh.

[The Cog]

TheFu is (as always) right. But I will add:

Although you can order ping to send via a given interface, you can't do that with rsync. I think you can ask it to use a chosen source address with --address=ADDRESS, this won't influence the direction that the routing table sends the packets in (It may influence the path any reply takes though).
Use ip route get 192.168.1.2 to see where they will be sent. Also ip route get 192.168.1.2 from 192.168.5.1 but I doubt the answer will change.

Full details of all the IP addresses involved would help us understand. There seem to be at least 3 devices from your description, and there will be 2 tunnel ends so that's at least 5 IP addresses to fill the picture.