Fix CentOS VM Ethernet Connectivity

My CentOS virtual machine sits on a local workstation and is bridged to the host’s Ethernet port, yet it can’t reach the internet—no DNS, no pings, nothing. The host itself remains fully online, so the fault is somewhere in the guest’s network stack or its virtual adapter settings.

I need a quick, methodical diagnosis that tells me exactly where the break is (interface config, routes, firewall rules, driver issues, etc.) and a permanent fix that survives a reboot. I can give you console or SSH access and will promptly supply any logs you request. However, I would like to have TeamViewer so that instructions can be relayed.

Acceptance criteria:
• VM reliably pings external IPs and resolves domain names.
• Solution persists after reboot.
• Brief summary of root cause plus the commands or configuration edits applied.