Tip #5: Network Troubleshooting with PathPing

Today's tip is on network troubleshooting with pathping, a command line utility included with Windows XP...

pathping is somewhat of a hybrid of the ping utility and the tracert utility... ping is typically used to determine whether network connectivity can be established with a host, and also to obtain statistics on the time taken to receive the response back from the host... tracert will display information on the hops, or interconnections used, to connect to a particular host...

pathping, however, will display statistics on the hops used to arrive to the host, and also provide response time information on each step of the connection... By finding where and if packets were lost along the route, you should be able to determine the exact location of the source of any network problems with a remote machine...

To use pathping, open a command prompt (Start/Run/cmd) and use the following command:
pathping whateverremotehost.com

The response should look similar to this:

Tracing route to google.com [64.233.187.99]
over a maximum of 30 hops:
 0  DESKTOP [192.168.0.101]
 1  192.168.0.1
 2  10.XXX.XXX.XXX
 3  68.XXX.XXX.XXX
 4  68.XXX.XXX.XXX
 5  68.XXX.XXX.XXX
 6  68.XXX.XXX.XXX
 7  72.14.197.54
 8  66.249.95.253
 9  72.14.236.26
10  72.14.236.175
11  216.239.49.226
12  64.233.187.99

Computing statistics for 300 seconds...
           Source to Here   This Node/Link
Hop  RTT    Lost/Sent = Pct  Lost/Sent = Pct  Address
 0                                           192.168.0.101
                               0/ 100 =  0%   |
 1    0ms     0/ 100 =  0%     0/ 100 =  0%  192.168.0.1
                               0/ 100 =  0%   |
 2   10ms     0/ 100 =  0%     0/ 100 =  0%  10.XXX.XXX.XXX
                               0/ 100 =  0%   |
 3    9ms     0/ 100 =  0%     0/ 100 =  0%  68.XXX.XXX.XXX
                               0/ 100 =  0%   |
 4    8ms     0/ 100 =  0%     0/ 100 =  0%  68.XXX.XXX.XXX
                               0/ 100 =  0%   |
 5   10ms     0/ 100 =  0%     0/ 100 =  0%  68.XXX.XXX.XXX
                               0/ 100 =  0%   |
 6   24ms     0/ 100 =  0%     0/ 100 =  0%  68.XXX.XXX.XXX
                               0/ 100 =  0%   |
 7   24ms     0/ 100 =  0%     0/ 100 =  0%  72.14.197.54
                               0/ 100 =  0%   |
 8   24ms     0/ 100 =  0%     0/ 100 =  0%  66.249.95.253
                               0/ 100 =  0%   |
 9   49ms     0/ 100 =  0%     0/ 100 =  0%  72.14.236.26
                               0/ 100 =  0%   |
10   51ms     0/ 100 =  0%     0/ 100 =  0%  72.14.236.175
                               0/ 100 =  0%   |
11   51ms     0/ 100 =  0%     0/ 100 =  0%  216.239.49.226
                               0/ 100 =  0%   |
12   48ms     0/ 100 =  0%     0/ 100 =  0%  64.233.187.99

Trace complete.

The application will then display the route taken to reach the host, and then it will check the response times for each hop along the route... Some routers and firewalls are configured to not respond to ICMP requests (the protocol used by ping and pathping), so hops with 100% loss can safely be ignored as long as hops further down the line appear up...

pathping can prove invaluable as a tool for detecting networking and latency problems, especially in VOIP and video situations where dropped packets and high latency can cause problems...