[FEATURE] - Allow LAN traffic

[dkoppenh]

Is your feature request related to a problem? Please describe.
I'd like to be able to connect to local LAN resources when I'm connected to an off-site VPN.

Describe the solution you'd like
A toggle switch on a connection that allows you to connect to local IP addresses, but push all other traffic to the tunnel (including that which is also going to a non-routable address on the VPN side)

Describe alternatives you've considered
I currently have AllowedIPs set up to handle this, but would have to manually change them if I want to access resources on a LAN with a different address range.

Additional context
The AllowedIPs calculator I use is https://www.procustodibus.com/blog/2021/03/wireguard-allowedips-calculator/

[gorman42]

It would surely be handy.

[ronandalton]

If anyone else tried that calculator tool and it didn't work for them (internet connection no longer working), make sure you don't include the IP range of the Wireguard interface and/or the configured DNS server in the "disallowed IPs" input box (non-routable addresses you really do want to go through the VPN). To do this I put all the local network IP ranges in the allowed IPs box and the VPN specific IPs in the disallowed IPs box, then used the result as the disallowed IPs input with an accompanying allowed IPs input of 0.0.0.0/0, ::/0. The page doesn't say anything about this and gives an example which does not work.

It tripped me up so I thought I'd mention it in case someone else had the same issue. Of course the implementation for this app would need to account for this as well (it is mentioned in the initial issue comment).