The admin can USE the TRACEROUTE command-line tool to inspect the location where packets are being dropped on the ROUTER.

Traceroute is a command-line tool used in real-time network troubleshooting to determine the path data packets traverse across the internet to their destination addresses. When you visit a website, the traffic must pass through multiple intermediaries before it reaches the website. The traffic passes through your local router, the routers of your Internet service provider, and onto larger networks, among other things.

Traceroute shows us the path that visitors take to get to the website. It also shows the length of time that each halt takes. If you're experiencing trouble accessing a website that appears to be operational, there could be a problem somewhere along the path between your computer and the website's servers. Traceroute would reveal the source of the issue.

In more technical terms, traceroute uses the ICMP PROTOCOL to deliver a series of packets (the same protocol used for the ping command.) The time-to-live (also known as TTL, or hop LIMIT) of the first packet is 1, the second packet is 2, and so on. The TTL is reduced by one each time a packet is forwarded to a new router. The packet is deleted when it reaches 0 and the router delivers an error message. Traceroute ensures that each router in the path discards a packet and responds by forwarding packets in this manner.