Common Networking Mistakes and How to Avoid Them

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Congratulations, you’re setting up a network! Maybe it’s your home network, a small business, or even a large company. Now that you have the job to complete what do you do?

Hopefully you have already been studying, or already passed a certification test such as the MCSA or Network +. If you have not, now is a great time to learn the best practices.

First, you must plan and define what the goal is. I’m sure you are saying “What? Why can’t I just plug in a router and switch? They should take care of everything, correct?” That is partially correct. Most routers can do a decent job of handling basic network information. Let me ask you this if you have one device that is not connecting, or is experiencing random drop offs, how do you troubleshoot without knowing your setup?

Whether it is a simple home network or a complex multi-office network, both have the same basic best practices, and network technicians can make the same common mistakes setting them up. Let’s look at some common mistakes and how to avoid them.

Failure to plan.

Planning is the key to understanding your network. Even with a home network, if you are having issues streaming TV or playing online video games, without planning you have no idea how the packets are traveling. For example, I once set up a home network for a family and made sure I documented every router, switch, wireless access point and all the end user equipment. Everything was working great, then suddenly they started having issues with multiple devices not connecting or getting severe lag. The ISP said it was not their issue, so I had to consult their network plan to troubleshoot. As I started comparing the information in the plan to the actual devices I noticed some strange IP information on some devices. The gateway address was wrong. After verification, I found that a wifi router had been added to the network with DHCP enabled which was causing some devices to get an additional hop before reaching the actual gateway. Having a plan and documentation allowed me to find the issue quickly and get it resolved.

My Windows Server 2016 certification really served me well in this situation. Proper planning is just one of the best practice recommendations I was able to glean from taking the Microsoft 70-741 exam, which covers how to implement network connectivity.

Failure to define IP device range and lack of standardization.

This is a common mistake on small networks because it is often assumed since it’s small it will be easy to troubleshoot, however, this mistake can also be seen on larger networks. So, what is an IP device range? While you can just let DHCP assign addresses randomly, do you know what device it is by looking at the address? If you have a device at 192.168.0.25 that is broadcasting like crazy on your network, how do you find it? One of my best practices is to set up my entire network with a similar scheme. Looking only at the last octet, 1 is always the gateway, 2-30 are infrastructures such as servers, managed switches, NAS, and so on; 31-50 are networked printers and scanners. This is enough range to cover devices that require a static IP address. I set DHCP to start at 51 and end at 200. If you need more than 150 address you need to subnet your network. The last 50 are left open for things such as IT use, testing and overflow. This structure allows me to quickly look at the network and identify what type of system is creating issues.

So how do we figure out how to manage the IP address ranges? By learning from the experts! INE’s Microsoft 70-741 course covers core and distributed network solutions, and this includes how to set up the IPv4 and IPv6 addressing, subnetting, and what to do when you have distributed branch offices.

Improper cable management

Cable management- Why does it matter? Cable management is a best practice that makes everything easier to troubleshoot, replace and upgrade. Have you ever walked into an infrastructure room and seen cables running everywhere randomly? We call this a “snake pit.” You must organize it before you can even start troubleshooting, which can be very time consuming. Being tidy with your cabling helps make troubleshooting a lot easier.

Basic cable management includes using different color cables for different classes of systems.

The list I use is:

● Yellow cables are for cross overs

● Red cables are for servers, NAS

● Blue cables are for switches into a conduit for wall jacks, as well as wall jack to desktop

● Black cables are for between switches, routers and infrastructure

● Green cables are used for temporary connections as needed

Another important part of this standard is properly labeling both ends of the cable with the device information. Do you know which device is plugged into which port on your switch? If not, your improper labeling could also cause a longer troubleshooting process. Time is money, therefore the longer systems are down, the more money your company loses. These are just a couple of my favorite cabling best practices, you can learn more with certification training such as CompTIA’s Network +.

Improper server placement

How can you improperly place a server, it’s all the same network, right? This is a best practice that gets overlooked by many when building their network. Your servers are the central point of your entire network, which means you’ll want to get the data to and from servers as fast as possible. Let’s look at this from a different perspective. Say you’re taking a car trip, you have two choices to get on the interstate freeway; you can pass all the towns or get on the local highway that goes through all the towns. It’s the same distance, but which is faster? The interstate freeway is faster because you do not have to slow down, stop, and reroute at every town. This is the same with your network, every time you add a switch, hub, router, or any device physically between the desktop and the server, you are slowing the information down. Even if your network is small, as an IT professional you should still pay attention to this. There are more best practices on items like server placement, and how to replicate servers among different geographical locations, which can be found in certification training such as Microsoft class 70-741.

Improper Wi-Fi placement

This is becoming a greater issue as wireless access use continues growing at home and in company offices. When you have a wireless network what steps can you take to minimize issues? This is a simple question with a complicated answer as every install and setup is different. One best practice is to set up the wifi access point in the center of the location where it will be needed the most, or add access points until the whole area is covered. Another habit you should get into is testing the wi-fi throughout the day and week. This sounds simple but you would be amazed how many wifi routers are set up on the opposite side from where most devices are being used (without installing an access point to improve coverage) because it was more convenient for the network technician. Constant monitoring allows you to find traffic spikes, and other issues before they grow bigger. I once was called in to help an office because they were losing connection to the network every day at noon. After testing the wi-fi unit and seeing nothing new connected, I started monitoring its signal strength with a signal meter. It took about 2 hours before I noticed the wifi channel flooded with bursts of noise. I started doing more physical snooping, trying to locate the transmitter and finally found it. One of the managers whose office was close to the wifi had hooked up a microwave oven because the break room was “too far away.” This unit was leaking all over the wifi spectrum every time it was used. RF noise can come from anywhere and many technicians do not recognize or look out for it. As a certified technology professional, not only will you have the knowledge to properly set up wifi, but also how to find and remove items that can be disrupting the network. Wireless systems like wifi are a big deal in our modern society. This is why training on these systems is included in certification courses by CompTIA’s Network +, Cisco’s CCNA now has a Wireless Specialization certification, and the Microsoft 70-741 exam covers remote access solutions, network virtualization, and private network solutions.

As you can see, Best Practices are vital to ensure common mistakes are avoided and your network continues to run smoothly. To learn more, view our courses for Microsoft products such as Windows Server 2016 by Melissa Hallock.