Using pathping to identify data transfer problems

Network performance and reliability greatly depend on flawless data transfer using TCP/IP protocols. You can find out whether data transfer is occurring flawlessly both inside and outside the company network using a fairly simple tool. Pathping is one of the most useful network diagnostic tools out there, second only to the better-known command-line utility ipconfig. System administrators and home users appreciate the flexibility and efficiency of this CMD command, especially when dealing with complex network environments.

Pathping is an easy-to-use diagnostic tool that builds on its predecessors tracert and ping and is described as being an evolution of them with even more extensive capabilities. This command-line utility has been available to users since Windows 2000 and can be used to obtain information about data traffic and to check the availability of specific hosts in a network. Pathping analyses are often an important step in initiating concrete actions aimed at network optimisation and troubleshooting. For network analysis, the command-line utility uses the Internet Control Message Protocol (ICMP).

The term ‘network latency’ is often used when talking about online data traffic. This refers to the amount of time it takes for a data packet to travel from the sender to the receiver. A long delay is especially critical when it comes to data-hungry applications.

A slow connection can, for example, significantly impact a person’s gaming experience in an online game or lead to image stuttering and dropouts when streaming videos. Video conferences and VoIP calls are also greatly impacted by high network latency. Likewise, if data traffic is too slow, this can negatively affect the process of retrieving a website. For example, when using online shops, the shopping experience can be hampered by wait times. Another potential network problem is data packet loss. This can have a noticeable impact on the efficiency and speed at which information is exchanged over local, national, and international networks. Pathping can help with this as well.

Pathping is great for detecting network problems such as cabling issues, data packet loss and speed degradation. During network analysis, this diagnostic tool sends a specific number of test packets to individual intermediate stations (called hops) over a defined period of time. Each hop on the way to the addressee (e.g. a website) receives a total of 100 ICMP echo packets. The addressed intermediate station (e.g. a router) then returns the data packets via Internet Protocol.

After evaluating these pings, pathping generates statistics showing the intermediate stations and the path followed by a data packet. The round-trip times (RTT) for a data packet from source to destination are also recorded. Data loss, operational problems and transfer problems are thus quickly identified. This makes it possible to locate overloaded or malfunctioning routers and computers that are obstructing and slowing down data traffic.

The command-line utility pathping can be used via the Windows command-line terminal (cmd.exe.). You can access the terminal through the Run dialogue box:

1. Use the keyboard shortcut ‘Windows key + R’.
2. Enter ‘cmd’ into the input field of the Run dialogue box.
3. Click OK.

Like all command-line utilities, pathping is used with a text-based syntax. When writing the command syntax, you need to use the following template:

Since pathping also performs calculations and sometimes traces more complex routes with numerous intermediate stations, it may take longer to perform the network analysis to display the final results. The options listed in the syntax are therefore mainly for managing the command more precisely. For example, pathping will perform some routing routines based on preset defaults if the user does not specify any. If these defaults are reduced, such as shorter timeouts, the analyses of more complex network routes in particular can be sped up. This would require the following syntax to be used in the code:

Instead of using the default wait time of 3,000 milliseconds, this code will shorten the time per intermediate station to 600 ms. You can also limit the number of hops that pathping should include in the analysis. You must enter a number after the option ‘/h’. If you include three hops, the code will look like this:

Limiting the analysis to the first few hops can be useful if you have already found the problem in your own local infrastructure and just want to check a revised router configuration and the transfer to the next station (e.g. to the Internet provider).

In the first part of the analysis, the pathping command essentially functions in the same way as its predecessor tracert and lists the individual intermediate stations numbered consecutively. By default, host names are displayed first and then their corresponding IP addresses (e.g. the router ‘fritz.box’ with the IP address 192.168.178.1). For the ‘fritz.box’ example, the first few hops of the route would look like this:

You can then glean various information from this data. The hop example (IP address: 212.227.120.13) took an unusually long time for a ping response (300 ms). The evaluation ‘10/100 = 10%’ shows that 10% of the data packets sent directly to this hop were lost. The value ‘8/100 = 8%’ shows that eight packets that passed through the hop were discarded. The line below this information indicates that on the path to the next hop (IP address: 62.53.11.131), 13% of the data packets were discarded.

Packet loss and delays can indicate that the CPU or the local packet buffer memory for the corresponding router was overloaded at the time of the request. Problems that are core to the router could also have a negative effect. In this case, the router would then need to be better configured or replaced if it has a technical defect.

In addition to the previously mentioned examples, there are other parameters that can be added to pathping for network diagnostics. In the following table, you will find the most important options with explanations for each.