TRENDnet TDM-C400 User's Guide - Page 174

TDM-E400 / TDM-C400 ADSL2+ Ethernet Modem Router User's Manual Using the Traceroute Utility You can use the traceroute utility to view the IP addresses of all the hops that an IP packet makes from the Ethernet Modem Router on its way to an Internet destination. You can use the results of a traceroute to determine where a delay or transmission error is occurring. The traceroute utility sends a specified number of ping or UDP packets (3, by default) to the first router in the path toward the specified destination computer. These packets carry a time-to-live (TTL) value of 1. The TTL value is a counter which is reduced by 1 by each router that receives the packet. The first receiving router reduces the TTL from 1 to 0 and responds with an ICMP message indicating that the packet has been discarded. The receipt of this message enables the Ethernet Modem Router to determine: f that the ping/UDP packets reached the initial router, and f the packet's approximate time in transit. The traceroute utility then sends out packets with a TTL of 2. The First router that receives the packet reduces the TTL to 1 and routes the packet to the next hop. The second router that receives the packet reduces the TTL to 0 and responds with an ICMP timeout reply. The next set of traceroute packets has a TTL of 3, and so on, until the traceroute packets reach the destination computer. The destination computer replies with an error message that signals the completion of the traceroute. To perform a traceroute, you must know the destination IP address or host name. Follow these steps to perform a traceroute: 1. From the Diagnostics page, click . The Diagnostic - Traceroute page displays: 174