Final answer:
The administrator can use the traceroute command to locate and determine the TTL of the furthest reachable node when the ISP is experiencing network outages. Traceroute shows the route that packets take to reach a network host, including the TTL of each hop.
Step-by-step explanation:
To quickly locate and determine the TTL (Time To Live) of the furthest reachable node when a company's ISP is experiencing network outages, the administrator can use the traceroute command. This command is designed to show the route that packets take to reach a network host. It provides information about each hop along the way, including the IP address, round trip time, and the TTL of the response from each hop. The TTL value helps understand the lifespan set for a packet before it is discarded or re-validated.
The ping command is used to test the reachability of a host and measures the round-trip time for messages sent from the originating host to a destination computer. The route command is used to display or modify the IP routing table, and the arp command displays or modifies the IP-to-Physical address translation tables used by address resolution protocol (ARP).