Depends. If the zone responsible for whatever resolves to that IP is hosted locally - then DNS request would stay local.
If the service behind that IP is running locally - then all traffic would stay local. Network stack would be smart enough to not run circles to find itself.
Yeah, the router ought to know that public IP belongs to a device in its own network unless you're doing stuff like running your own router behind an ISP provided router and just forwarding ports instead of maintaining IP assignment / routing tables
Depends. If the zone responsible for whatever resolves to that IP is hosted locally - then DNS request would stay local.
If the service behind that IP is running locally - then all traffic would stay local. Network stack would be smart enough to not run circles to find itself.
Yeah, the router ought to know that public IP belongs to a device in its own network unless you're doing stuff like running your own router behind an ISP provided router and just forwarding ports instead of maintaining IP assignment / routing tables
I think OP is referring to NAT hairpinning though.
Tell that to my opnsense box that refuses to NAT mirror.