Trace IP How To

Last Updated 3/11/2010

How to trace the IP address in Windows XP or Windows 2000

How the TRACERT Command Works

The TRACERT diagnostic utility determines the route taken to a destination by sending Internet Control Message Protocol (ICMP) echo packets with varying IP Time-To-Live (TTL) values to the destination. Each router along the path is required to decrement the TTL on a packet by at least 1 before forwarding it, so the TTL is effectively a hop count. When the TTL on a packet reaches 0, the router should send an ICMP Time Exceeded message back to the source computer.
TRACERT determines the route by sending the first echo packet with a TTL of 1 and incrementing the TTL by 1 on each subsequent transmission until the target responds or the maximum TTL is reached. The route is determined by examining the ICMP Time Exceeded messages sent back by intermediate routers. Note that some routers silently drop packets with expired TTLs and are invisible to TRACERT.
TRACERT prints out an ordered list of the routers in the path that returned the ICMP Time Exceeded message. If the -d switch is used (telling TRACERT not to perform a DNS lookup on each IP address), the IP address of the near- side interface of the routers is reported.
The TRACERT command can be used to determine where a packet stopped on the network.

TRACERT Syntax

There are several command-line switches that can be used with TRACERT, but they are usually not needed for standard troubleshooting.
TRACERT syntax:
tracert [-d] [-h maximum_hops] [-j host-list] [-w timeout] target_name
Parameters:
  -d
        Specifies to not resolve addresses to host names.
  -h maximum_hops
        Specifies the maximum number of hops to search for target.
  -j host-list
        Specifies loose source route along the host-list.
  -w timeout
        Waits the number of milliseconds specified by timeout for         each reply.
  target_name
        Name or IP address of the target host.

How to trace the IP address in Linux or Unix

Traceroute Syntax

traceroute [-m #] [-q #] [-w #] [-p #] {IP_address|host_name}
Parameters:
  -m
        Set the maximum Time To Live (TTL) for the trace, measured as the number of hosts the program will trace before ending, default of 30
  -q
        Set the number of UDP packets to send for each setting, default of 3.
  -w
        Set the amount of seconds to wait for an answer from each host before giving up, default of 5
  -w
        Specify the other host's invalid port address, default of 33434
  IP_address|host_name
        Name or IP address of the target host.