Routing setup with pfSense package

[Corey Boyle]

I just found that the VPN Netmask option in the pfSense tinc GUI is
related to the "netmask" option in /usr/local/etc/tinc/tinc-up

ifconfig $INTERFACE 192.168.117.1 netmask 255.255.0.0

What exactly is this line doing? Is it assigning the address that my
lan adapter has to the tunnel interface as well?

I'm interested in using tinc in production, so I'm trying to learn as
much as I can about what's under the hood.