Your host MacOS can't connect to the internet? Your Linux VM OS can't connect to the internet? Both OSes can't connect to the internet?
What can they connect to?
What network connection does your Mac use? Assuming it's wifi, are there any controls on the access point which would stop multiple IP addresses or MAC addresses working on a single "port" / "session"?
You do know if your Mac is using a wired or wifi connection?
What switch or access point does it connect to? That's where there might be a port security configuration.