Traceroute

You should check back periodically to see if new techniques have been added.

Is the server down or is there some other problem?

To trace the route:

• On Unix: traceroute www.domainname
• On Windows(from a MS-DOS prompt) tracert www.domainname or use the graphical traceroute tool PingPlotter.

Of course, if you can't get to the machine, you may not be able to look up the name, so you can also use:
tracert 198.49.126.154

Sample Windows tracert

C:\Documents and Settings\Charles>tracert ha.clarkecomputer.com

Tracing route to ha.clarkecomputer.com [198.49.126.154]
over a maximum of 30 hops:

  1     *        *        *     Request timed out.
  2   138 ms    47 ms     8 ms  ge-2-3-ur01.fortcollins.co.denver.comcast.net [68.86.129.209]
  3    10 ms    13 ms    13 ms  te-9-3-ur02.longmont.co.denver.comcast.net [68.86.103.157]
  4    24 ms    14 ms   186 ms  te-9-1-ur01.longmont.co.denver.comcast.net [68.86.103.161]
  5    20 ms    35 ms    69 ms  te-3-1-ar01.denver.co.denver.comcast.net [68.86.103.154]
  6    28 ms    82 ms   105 ms  te-0-6-0-1-cr01.denverqwest.co.ibone.comcast.net [68.86.84.69]
  7    78 ms   102 ms    37 ms  te-0-0-0-0-cr01.stratford.tx.ibone.comcast.net [68.86.84.54]
  8    66 ms    55 ms    59 ms  te-0-7-0-4-cr01.losangeles.ca.ibone.comcast.net [68.86.84.53]
  9    87 ms    51 ms    47 ms  68.86.89.110
 10    83 ms    97 ms   180 ms  66.192.245.68
 11   210 ms    87 ms    84 ms  ns.clarkecomputer.com [198.49.126.154]

Trace complete.

What you will see is a list of machines that the packets go through from where you ran tracert to the server. The output will include 3 times (in milliseconds) for how long it took a packet to reach that machine and return. If the packet did not return before the timeout, an asterisk(*) will be listed instead. In the tracert above, the first node doesn't respond to ICMP packets and that is why there are 3 asterisks. Once the tracert reaches the target machine the output will stop.

Possible problems and their cause:

Output ends in all asterisks for times (for the last few lines).

Target machine was unreachable - the problem is probably at the last machine listed.

A loop where one machine is listed repeatedly (either by itself or in a loop with some others).

This indicates a routing problem at the machine(s) where the listing repeats.

IP addresses are listed, but no names

You are unable to do a reverse lookup on the IP address to get the correct name for that machine. If this happens for all the machines(and will also result in slow output), then something is wrong with your DNS(Domain Name Server) settings or the actual DNS server. Check your entries in Start->Settings->Control Panel->Network->TCP/IP->DNS Configuration. Try a tracert to the IP addresses you have listed.

Other places you can try tracerouting to see if the machine is down or you can't route to it are:

• www.fortnet.org
• www.tummy.com

NOTE:If you are behind a firewall, tracert may quit giving useful information at the firewall.

If you have problems understanding the output from tracert, copy it into an email and send it to me and I will help you find the problem. To copy it: In the MS-DOS window, choose the select button (the dashed square), drag your mouse over the text, choose the copy button (the two sheets of paper) and then paste it into your email program. The way to paste may different for your program, but <SHIFT>-<INSERT> (holding down the Shift key while hitting the Insert key) works with most.

I can get to the machine using tracert, but cannot load my web pages.