As a network engineer/professional, half the job you are responsible for is solving problems and putting out fires in your organizations network. Once a network is designed, implemented and commissioned, your job becomes keeping the network running smoothly. This means you become a problem solver for the users of the network.
One of the most important skills for any network engineer or network professional is TroubleShooting. When something goes wrong on the network, you have to find the solution. Quick efficient troubleshooting is the mark of a great network engineer.
The 4 tools and methods described below, are a must know for successful troubleshooting. And best of all these tools are all either FREE downloads or FREE tools built into most operating systems. Let’s take a look at them.
PING
This is the first and most important tool in a network engineers toolkit. PING was thought to stand for Packet Internet Groper, however Ping’s author (Mike Muuss) says its name is derived from the sound that comes from sonar. PING is a network utility that is used to test reachability on an IP Network. It will send IP Packets (ICMP) across the network to a specified destination to test if a host is reachable and if that host will respond. It will also measure the amount of time taken for the destination host to respond.
This is the first and most important tool you have at your disposal. When an issue is reported on the network, the first test to carry out is to check if the resource reported to be down is reachable. A quick PING test to your networks default gateway and then to the resource thought to be down is often the first step in troubleshooting. depending on the result of your PING test, you will know if something is wrong or not.
PING is a great, free and almost always built in utility that makes your life of troubleshooting so much easier. Some variations of ping exist, like free online ping tools like the one found at ping.eu. If you ask me nothing beats an old fashioned ping, as the first step in your network troubleshooting.
Trace Route
After PING, my most used free, built in utility is TraceRoute. As the name suggests, traceroute helps you trace the path (network hop by network hop) that your packet/traffic takes to the destination host. This tool is great to use to know exactly which path is used to get traffic from your network to another.
Traceroute is fantastic to use when your PING test fails. When the destination you tried to reach using PING is down, your next move is a traceroute. It will show you at which point in your path your traffic is falling off. This is helpful because it lets you know if the device that is failing to transmit your traffic is yours or if that device is outside your network. Often times I find that my traffic is failing once it enters my ISP’s network. With this info, I quickly contact my ISP and send them a copy of the trace I have done.
Think of TraceRoute as a PING that leaves you a trail of breadcrumbs to follow. It lets you know which devices are passing your traffic along to get to the destination. More importantly, in cases of a failure to get to the destination, it lets you know which device is failing in the chain.
Putty
Unlike the two previous tools, Putty is not a built-in software utility, Instead its an open source (free) terminal emulator. It is basically a downloadable application that allows you to log into your network devices remotely and interact with them. Putty is a command line terminal emulator that allows you to log in using several options, like SSH, Telnet, SCP, Physical Serial port etc.
This lightweight little app is just amazing. You don’t need to install it, instead you can just run it on your windows machine. Operating systems like Mac OS and Linux based systems have built in terminals, hence there is no need for putty. However if you are using a windows machine, putty is a quick and easy alternative to allow your remote connections with your devices.
Other terminal emulation softwares are available for free download and purchase. however nothing beats putty if you want a free light application to use to interact with your network devices. Its just awesome.
WireShark
Wireshark is the most popular network protocol analyzer in my books. It’s a free (open source) application that lets you capture and analyze all the traffic that is flowing through the network. its free, easy to install and easy to set up. Wireshark allows you to dive deep and really analyze what is going on in your network.
Think of wireshark as a magnifying glass which lets you take a peek at the traffic passing through your network. Even though it’s so easy to get started with wireshark, in the right hands it really is a powerful tool that can be used to solve all kinds of issues on your network.
Basically wireshark will monitor and measure network traffic and trends to help you analyze and solve problems on your network. This tool really is one of the best at what it does out their. Check out this link for some free wireshark training on cybrary’s site. Here’s another great tutorial on how to use wireshark from LifeWire.
Your take home is this
if you are hearing about any of the above tools for the first time then great, you may have just come across something that will save you hours in the troubleshooting struggle. If you know all of the above tools, check out some of the links I have shared, you will find some useful details about how to use them.
I hope what i have shared will help you on your journey to being an awesome network engineer. For more cool resources, check out my resources page. You will find loads of free platforms that can help you learn more and become better at what you do.