TRENDnet TDM-E400 - Manual (Page 174)

TDM-E400 / TDM-C400 ADSL2+ Ethernet Modem Router User’s Manual
174
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: