Every time I have occasion to look at the Windows command line documentation, I seem to discover something new. Admittedly this is because I don’t really look for new stuff all that often…

The year’s discovery for 2008 might be Pathping which is a Windows based command-line tool (for Windows cmd) used to provide information about the path data takes to its intended destination, network latency and network loss at intermediate hops between a source and destination.

It’s a TCP/IP based utility that can be used when looking for errors in network. It does this by sending echo requests via ICMP and analyzing the results. ICMP stands for Internet Control Message Protocol. ICMP is an extension to the Internet Protocol (IP - part of the TCP/IP protocol suite). ICMP supports packets containing error, control and informational messages.

Like tracert, pathping will discover the route IP traffic will currently take to from your machine to a particular target on the internet, and how long each hop takes. But while tracert just shows you three samples for the timing to each hop, pathping runs for a few minutes, and sends out a much larger number of packets - 100 per hop by default. It then displays the average performance and packet loss for each hop in the chain. Since timing and packet loss can vary quite widely, three samples often isn’t enough to characterise the quality of your connectivity, so pathping can give a better picture of network health between distant machines.

A sample output could be:

pathping -n server
 
Tracing route to server [10.1.1.5]
over a maximum of 30 hops:
  0  10.1.2.1
  1  10.1.1.1
  2  10.1.1.5
 
Computing statistics for 50 seconds...
            Source to Here   This Node/Link
Hop  RTT    Lost/Sent = Pct  Lost/Sent = Pct  Address
  0                                           10.1.2.1
                                0/ 100 =  0%   |
  1   35ms     0/ 100 =  0%     0/ 100 =  0%  10.1.1.1
                               13/ 100 = 13%   |
  2   28ms    16/ 100 = 16%     3/ 100 =  3%  10.1.1.5
                                0/ 100 =  0%   |
 
Trace complete.

PathPing is supplied in Windows NT, Windows 2000, Windows 2003, Windows XP and Windows Vista.

Finally it’s nothing spectacular that can’t be archieved otherways but it will ease your work in some cases.