How To Troubleshoot Common Network Issues Like A Pro

Today network dependability is essential for both home and corporate users. Network problems will inevitably arise even with technological advancements. Reducing downtime and maintaining network functionality can be achieved by promptly identifying and fixing these issues.

Network troubleshooting can be intimidating, but with the correct strategy, common errors can be fixed fast.The ability to recognise and comprehend the issue is essential for efficient network troubleshooting. After identifying the issue, the next step is to diagnose and resolve it. This may involve checking hardware connections, rebooting equipment, or using diagnostic tools.

In this blog we will explore how to troubleshoot common network issues like a pro. This would be helpful for students, network engineers and IT admins.

Table of Content:

What Is Network Troubleshooting?
Basic Network Troubleshooting Checklist
5 Common Network Issues & How To Fix Them
Common Tools for Troubleshooting Network Issues

What Is Network Troubleshooting?

The methodical way of identifying and fixing issues inside an IT network is known as network troubleshooting. It entails figuring out the underlying cause of a network problem and putting a fix in place to get it working again.

Currently, 91% of companies encounter at least one network interruption every three months. In a time when technology plays a big role in our everyday business operations, downtime can result in significant losses in productivity, finances, and reputation.

Consider Facebook, which experienced a 14-hour outage in 2019 that cost the company an estimated $90 million. Strong network troubleshooting skills are necessary to reduce this harm and improve network reliability.

Basic Network Troubleshooting Checklist

Finding and resolving network issues early on is crucial since they can hinder business operations and affect performance.This basic network troubleshooting checklist can assist you in locating and fixing network problems quickly.

Step 1: Identify the Problem & Check the Physical Connections
The most important thing is to gather all of the network's and its component parts' information from various places in a single place.

Now, examine every network equipment, cable, and router to identify any problems.Keep track of the problem, such as a slow internet connection, LAN connectivity problems, or any other configuration setting issue. To solve basic network issues, teams can also try restarting devices like the router, PC, and modem.

Step 2: Fix the Duplicate IP Addresses Entry
Enter "ipconfig" at the command prompt to see if your computer or device is getting a working IP address. An invalid IP address is assigned if the first digits of the address start with 169.

Step 3: Run a Quick DNS Check

To identify server issues, use the "nslookup" command. Responses like "rejected," "timed out," or "server failure" indicate that the problem is with the DNS server for the destination URL. Use an NS lookup tool to confirm the results of the NSlookup command. If the results support one another, there is a problem with the intended website. Using DNS filter alternatives can help to resolve such difficulties more efficiently.

Step 4: Check Malware Protection
Ensure your router's firmware is up to date and that the drivers and software on your devices are of the latest versions. Additionally, examine your malware prevention software to see if any programs, applications, or settings are affecting the functionality of your network.

Step 5: Review Database Logs

One of the most efficient ways to find and fix issues with network performance is to analyse logs. Logs provide comprehensive information on each program, device, and application to help identify the root cause of the issues.

5 Common Network Issues & How to Fix Them

1. Slow Internet Speed

It refers to decreased network data transfer rates that affect activities like online browsing, video streaming, and file downloads. Some of the causes include network congestion, old hardware, misconfigured network settings, and bandwidth limits. Some of the fixes include updating hardware and firmware, optimising router settings, and increasing bandwidth.

How To Fix This?

Upgrade Bandwidth: Use tools like Wireshark or ntopng to analyse bandwidth utilisation and determine whether an upgrade is necessary for the network or not.
Change Router Settings: Use command-line interfaces (CLI) to change settings such as Quality of Service (QoS), TCP/UDP timeouts, and multicast rates.

2. DNS Resolution Issue

DNS server outages, improper DNS setups, or network security settings obstructing DNS communication are some of the causes. Diagnosing entails verifying DHCP and DNS server settings and evaluating DNS resolution using programs like nslookup or dig. Potential fixes include changing to a more dependable DNS server, modifying firewall configurations, or clearing local DNS caches.

How To Fix This?

Debug DNS Settings: To debug DNS resolution issues at the client or server level, use dig or nslookup.
Clear DNS Cache: To remove the local DNS cache, use sudo systemd-resolve –flush-caches on Linux or ipconfig /flushdns on Windows.
Switch To a More Reliable DNS Server: In comparison to ordinary DNS services, secure DNS services like Cloudflare's offer improved privacy and security by encrypting DNS requests, which can guard against DNS eavesdropping and spoofing attacks. They also frequently offer faster response times and greater dependability.

3. Network Congestion

Data transmission slows down when there is too much traffic on a network. This frequently happens when too much data is transferred over the network, exceeding its capacity. Network traffic must be longitudinally monitored in order to identify congestion, and sources of excessive utilisation must be identified. Implementing Quality of Service (QoS) to provide priority to important traffic, improving network infrastructure, or rearranging the network architecture to more fairly distribute traffic are some solutions.

How to Fix This?

Implement Quality of Service (QoS) Rules: Set up QoS policies by giving priority to critical traffic using iptables or router CLI/web configuration interfaces.
Improve Network Infrastructure: Find bottlenecks by using network monitoring tools. Upgrade your switches and routers to higher throughput models.
Optimize Traffic: Use hardware load balancers or technologies like Haproxy to apply load balancing and implement VLANs for effective traffic segregation.
Furthermore, a thorough understanding of Ethernet technology is required due to its integration into wireless networks.

4. IP Address Conflicts

This happens when the same IP address is given to two or more devices on the same network. As a result, the impacted devices experience problems connecting to the network. Manual IP assignment or DHCP configuration mistakes are among the causes. Resolving IP conflicts entails adjusting the DHCP server settings, assuring proper manual IP allocations, or establishing static IP addresses for important devices.

How To Fix This?

Implement Proper DHCP Configuration: Examine DHCP server configurations, confirm lease terms, and check scope. To test a DHCP server, use dhcping.
Static IP Assignments: Static IP addresses can be assigned automatically or manually using network management software, network interface configuration files, or configuration management tools.

5. Packet Loss

When data packets fail to arrive at their intended destination, network applications might experience disruptions in performance. Common causes include network congestion, defective hardware, and low-quality network connections. Using network diagnostic tools like ping, mtr, or packet sniffers is necessary to identify packet loss. Addressing network bottlenecks, repairing damaged hardware, and optimising network configurations can all help to improve traffic handling efficiency.

How to Fix This?

Congestion Management: Use tools such as tc on Linux to apply QoS to routers and switches in order to prioritise and shape traffic.
Identify & Fix The Source: Use packet sniffing tools such as Wireshark or tcpdump to figure out where packet loss is occurring. Check for network congestion or problems with the physical layer.

Common Tools for Troubleshooting Network Issues

These network troubleshooting tools range from simple command-line-based utilities to more extensive and complex solutions that allow for a systematic, efficient, and proactive approach for network troubleshooting.

Some of the network troubleshooting tools are as follows:

Ping
Tracert
PuTTY
Route
Netstat
Ipconfig/ ifconfig
Nslookup
Pathping/MTR

FAQ's

What are some network issues?

Some common network issues are slow internet speed, DNS resolution, Network Congestion, IP Address Conflicts and Packet loss.

What are the four types of DNS?

The four types of DNS are root nameservers, TLD nameserver, authoritative nameserver and recursive resolvers.

Why is network troubleshooting important?

Network troubleshooting is critical because it helps IT managers understand network component faults, reduce downtime, and improve the network's Quality of Service (QoS) for users.

What is the OSI model in networking?

The Open Systems Interconnection (OSI) model is a conceptual framework for organising network communication functions into seven levels.

What are the steps involved in network troubleshooting?

Network troubleshooting consists of seven steps: 1) Identify the issue, 2) Create a theory of probable cause, 3) Test the theory, 4) Create a plan of action, 5) Put the answer into practice, 6) Confirm complete system functionality, and 7) Record the procedure.