[CentOS] firewalld question

Hi all!

I'n wondering if it is possible to have Centos-7 automatically change firewall zones, depending on the network we conect to.

my default zone is "home" and it has some ports open that probably shouldn't be open when I'm on someone elose's network.

so I'm thinking that if there's a way to have it always use home when I'm at home, and external when I'm not, it would be great.

I see that firewall-cmd has a ton of options, but not sure which one(s) I'd need for switching. (I see one for setting default zone, but I didn't see one for setting current zone--maybe I'm blind).

I'm also not at all sure how to invoke it at a proper time,... perhaps some udev rules?

anyone got any wisdom they can drop on me?

thanks!