Wi-Fi and Hard-Wired Ethernet connection no longer works after High Sierra upgrade

I have a new MacBook Pro and recently updated macOS to High Sierra (10.13.3). However, since that time I have been unable to access the Internet via either WiFi or hardwired Ethernet connection (via Thunderbolt to USB+cable adapter). Internet to all other devices in my house (including both hardwired and WiFi) work just fine. Only the new MacBook Pro cannot connect to the Internet.

Let me know if there is anything I can do to remedy.

Thanks, Rob