Without having to do any thing, try pinging 4.2.2.2 or 8.8.8.8 sa workstation mo.
If nakakaping ka, (assuming na windows PC), try the command "nslookup" "server 4.2.2.2" then input a url, tingnan mo kung makakaresolve.
If you have access to the router, baka pwede mong tanggalin yung WAN connection ng router, then ilipat mo sa PC mo.