For smart administrators to troubleshoot, and then resolve, network failure issues quickly, they need to assess the stability of the network and find out where the disruption has occurred. And yet, an even smarter administrator would conduct a network stability test before a failure to spot any errors or weak spots prior to their causing a crash.
The definition of a network stability test can, therefore, be given as:
The process of using programs and commands to make sure every router and other devices being used to connect an intranet to the Internet – be they behind or beyond the territorial firewall – is up and running. It also involves making sure all the authorized data on the network is safe – both in motion and in resting states.
How can you test network stability?
There are several steps that need to be taken when testing a network’s stability. They include:
Network connectivity should never be lost; period. Apart from being up, it should also be fast and not prone to dropping packets. This can be done using three methods:
- There are tools out there that help administrators keep track of their networks. One such tool is the Paessler PRTG Network Monitor (FREE TRIAL). This is an all-in-one network monitoring suite of programs that keep a constant eye on the connectivity between a host network and popular domains like Google, for example, which aren’t expected to be down – ever.
- If you have a grasp of even the basics of networking, you can conduct the test yourself using free tools like Ping and Tracert. If you don’t, keep on reading and we will show you how it is done.
- Finally, connectivity and health testing can be done using third-party websites like Internet Health Test or Ping Can Be Useful. While these are the easiest way to go, they really don’t give in-depth information about connectivity issues – at least not for free.
Only the right type of data should be transported on a network and not, for example, spam data from an attacker on the outside. In another scenario, servers shouldn’t be backed up during peak processing hours when they could hog the bandwidth.
Administrators should, therefore, keep track of what data packet is passing through their networks. They can use numerous deep packet inspection and analysis tools found on the market which can be used to keep an eye on traffic and filter it as required.
Maintaining packet speeds
There shouldn’t be any attrition or loss of data speeds. Packets shouldn’t be dropped because the network is too congested, a router is not up or performing as well as it should be, or due to the fact that the specific packets have been blocked by mistake.
Administrators should have a plan as to how much bandwidth is allocated to every aspect of your data transportation – give more to VoIP and less to email traffic, for example, so audio communication doesn’t lag.
Here too, administrators can take certain defensive steps and corrective measures to remedy this particular issue.
Network administrators also need to make sure there are no breaches or unauthorized usage of the network, connected devices, and the data on it.
The ideal toolset to use here would be Network Intrusion Detection Systems (NIDS).
Finally, administrators know that their networks will only be stable as long as people who aren’t supposed to be on them are kept away. If outsiders keep meddling with data, configurations, and authorizations they will soon be able to hijack the network. They can then use it as a springboard for further attacks, hack the devices connected on it, or simply crash it.
Ok, now that that is clear let us get into the technical part of PING and TRACERT.
What does PING do?
PING is a tool that sends packets to a target server and listens for a reply. A successful reply of all (100%) the packets delivered means the target is up and running and there are no connectivity issues. On the other hand, any dropped packets indicate that there is a problem somewhere along the way, as is the case in the image below:
If the PING results in 100% loss, it could mean any (or all) of the connecting devices between the host machine and the target server are down.
What does TRACERT do?
TRACERT is a tool that sends packets to every single router that lies between the host machine and the target server.
In this case, though, the packets sent out will hop to every single router that is en-route to the target server and send a reply back to the host machine. Apart from confirming connectivity, each reply also includes the information of the next router in line so the subsequent packets have an address to target in the queue.
Based on this information, it becomes easy to see which routers are up, which one is taking too long to respond (it will be the one with the longest reply time), and which one is down (it will be the one that doesn’t send a reply back).
How to use PING to test for connectivity
PING is a versatile tool that can be run from the command-line interfaces (CLI) of operating systems like Windows, Linux, and macOS.
The steps involved [in Windows OS] are:
- Go to RUN -> Type CMD (or COMMAND) -> Then, type PING XXX.XXX.XXX.XXX (the target IP address) or PING ACME-Company.com (the domain name of the target network) in the CLI.
- “-t” is used to continuously ping a target when, for example, a remedy is being put in place and you want to keep monitoring to see if the issue has been resolved
For a full list of all the arguments that can be used, simply type PING /? at the prompt.
Error messages that show a reply from an unreachable device include Request Timed Out, Destination host unreachable, and Transmit failed (with an error code) – each of which tells a story about why there is an issue.
How to use TRACERT to test for connectivity
TRACERT is another command-line tool that helps with resolving connectivity issues. As mentioned, and in comparison to PING, this tool doesn’t just test the connection between two points. It also tests all the routers that are found along the route as the packets that are sent hopping to and from each of them.
Any interruption in the connection becomes evident when the packet ceases to return with a reply from the device. This indicates that the silent device is the one to check out.
Once executed from the CLI, the command sends a UDP packet to all the routers that lie between the origin and target address and then waits for a reply – again, if there is one, that is.
The basic syntax of the TRACERT command looks like:
TRACERT XXX.XXX.XXX.XXX or TRACERT domain-name.com (the target IP address or domain name)
- “-h” is used to set the number of hops that can be used to reach the target device
For a full list of all the arguments that can be used simply type TRACERT /? at the prompt.
Conducting network stability tests
Well, we have just seen all the tools you will need to conduct a network stability test. For those of us that don’t really want to be bothered with command-line interfaces, we have also seen there is a collection of tools you can use to achieve each objective of a network stability test.
Depending on your choice of tools and the frequency required, you can schedule or run them to see the status of your network’s stability at any given time.
Are there any tools you prefer to use or think would do the job better? Let us know in the comments section below.