Is there a way to setup an isolated guest connection (WiFi) on the Sonic SmartRG router that is password protected? I am hoping to allow a guest device to connect and have internet access but no access to anything else on my network..
Yeah you should be able to do that. Our public facing wiki article on the SmartRG has some more information regarding how to set up guest networks:
https://wiki.sonic.net/wiki/SmartRG_SR5 ... t_Networks