Info-x: A Brief Look At: Tracert

Message

   Description: 

Executed from the DOS command prompt.

This diagnostic utility determines the route taken to a destination by sending 

  Internet Control Message Protocol (ICMP) echo packets (like ping) 

  with varying 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 is supposed to send back an I C M P Time Exceeded message to the 

  source system. 

  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. Notice that some routers silently drop packets with 

  expired time-to-live (TTLs) and will be invisible to tracert.

Parameters:

    tracert [-d] [-h maximum_hops] [-j 

      computer-list] [-w timeout] target_name  

    -d

    Specifies not to resolve addresses to computer names.

    -h maximum_hops

    Specifies maximum number of hops to search for target.

    -j computer-list

    Specifies loose source route along computer-list.

    -w timeout

    Waits the number of milliseconds specified by timeout for each reply.

    target_name

    Name of the target computer. 

Example:

            C:\\>tracert www.altavista.com 

        Tracing route to altavista.com [204.152.190.69] 

          over a maximum of 30 hops: 

        1 <10 ms <10 ms <10 ms gateway1.alcom.co.uk [212.47.64.253] 

          2 <10 ms <10 ms 16 ms midgard-constellation.vertex.ipf.net.uk 

        [62.164.128.13] 

          3 <10 ms <10 ms 16 ms c4700.ipf.net.uk [62.164.129.2] 

          4 * 78 ms 93 ms linx.london.above.net [195.66.224.76] 

          5 78 ms 94 ms 94 ms iad-lhr-stm-4.iad.above.net [216.200.254.77] 

          6 156 ms 188 ms 187 ms sjc-iad-oc12-2.sjc.above.net [216.200.0.22] 

          7 343 ms * 312 ms pao-sjc-oc12-2.pao.above.net [207.126.96.65] 

          8 187 ms 203 ms * mibh-above-oc3.pao.mibh.net [216.200.0.10] 

          9 203 ms * 187 ms www.altavista.com [204.152.190.69] 

        Trace complete 