You’re going to run into network issues during normal operations—in part because so many kinds of errors can cause noticeable problems in your network. Identifying the root cause of each issue is critical and to do so successfully, you want to make sure you have the right network troubleshooting solutions in your arsenal before wading in. This helps ensure you have a clear understanding of the scope of the problem before you attempt any network troubleshooting steps.
This article will offer a basic network troubleshooting checklist for getting started, as well as some recommendations for applications helpful for diagnosing network issues. My top pick for network troubleshooting tools is SolarWinds® Network Performance Manager, as the best all-around option with easy-to-use features. However, if you’re focused on network device configuration, which is also critical for troubleshooting purposes, consider SolarWinds Network Configuration Monitor or Kiwi CatTools for smaller businesses.
Network Troubleshooting Steps
Gathering the right information can help direct you to the root cause of the problem, increasing your chances of fixing the issue the first time. The following steps offer a solid approach for collecting the right information you’ll need to properly begin troubleshooting.
- Ensure all network hardware is properly connected, turned on, and working. If the issue is a simple matter of reconnecting a loose cord or reactivating a router that got switched off by mistake, discovering this early will save you a lot of grief down the line when you’re troubleshooting network issues.
- If everything is connected and working, the next step is to power cycle your modem, router, end-user devices, and other affected hardware. This will often take care of minor issues—just remember to let each device remain powered down for at least a minute before turning it back on.
- Next, open the command prompt and enter ipconfig into the terminal. Toward the end, you’ll see “IP Address” and “Default Gateway” fields. The first is the IP address assigned to your computer. If the first three numbers are 169, then the address isn’t valid—any other number means your device address is valid. The Default Gateway field is the IP address of your router.
- In the command terminal, type ipconfig /release, then ipconfig /renew. This will clear your device’s current IP address and request a new one from the router. If this doesn’t resolve the issue, connect the computer directly to the modem via Ethernet. If this allows you to properly release and request new IP addresses, then you now know the issue is with the router.
- If the router is working properly and your device still has an IP address beginning with 169, then the problem likely lies between the router and the internet. Using tools like ping and tracert (more on these below) can help test whether you’re still able to connect to the internet. Open the command prompt and enter ping 220.127.116.11 to ping the Google DNS servers—if the ping attempt fails, the command prompt will provide some elementary data about the cause. To use tracert, open the command prompt and type tracert 18.104.22.168. The difference between ping and tracert is the latter will display each hop between the router and the Google DNS servers, which will reveal if there’s a specifical point along the pathway causing the error. If the error appears early in the pathway, then the source is likely on your local network.
- The next step is to run a DNS check. Enter nslookup in the command line to check whether the server you’re attempting to connect to is experiencing problems. To continue using the Google example: if you run a DNS check on google.com and receive messages like Network Is Unreachable, No Response from Server, Refused, Server Failure, or Timed Out, then the source of your issue may be with the DNS server of the site you’re attempting to access.
- By this point, most issues should be resolved, or it should at least be clearer where the root cause lies. If you’re still experiencing network problems, the next step is to contact your internet service provider to check whether they’re experiencing network issues as well. Use a smartphone to check nearby outage maps.
- Next, confirm your antivirus and anti-malware solutions are up to date and operating. If either has flagged anything that could be impacting your network, investigate immediately.
- Finally, going over your database logs is also a good idea, as full or malfunctioning databases can have wide-reaching ripple effects that carry over and impede the flow of regular network performance.
Recommended Network Troubleshooting Tools
While ping and tracert are useful tools (as discussed further below), they’re simple command-line prompts and do not provide the comprehensive level of data the leading network troubleshooting software and monitoring solutions can. The following are some of the best options available, each of which is well worth the investment.
1. SolarWinds Network Performance Monitor (NPM) Free Trial
NPM is a comprehensive tool designed to help you rapidly detect and resolve network performance issues. The application offers multi-vendor network monitoring, intelligent maps that automatically chart the physical and logical relationships between your devices, and hop-by-hop analysis of your most important network paths, making it simpler to correlate information from across your entire network and more effectively troubleshoot network latency issues.NPM is designed to scale for larger environments and includes efficiency-boosting features, like a customizable smart alerting system designed to help separate the network troubleshooting alerts requiring immediate action from the usual flood of notifications and more.
2. SolarWinds Network Configuration Monitor (NCM) Free Trial
NCM works a little differently from NPM. This tool uses automation solutions to cut down on network troubleshooting time by detecting device misconfigurations that could be impacting system performance. This has the added benefit of being an important security feature. NCM proactively monitors the configurations for all your network hardware and can automatically restore the approved settings if deviations are detected. The tool centralizes device monitoring, configuration, and management into a single application designed for you to deploy updates and changes across your network quickly and easily.
Using NPM and NCM together creates a powerful network troubleshooting, monitoring, and management tool that allows you to see how to monitor your entire environment for signs of small, seemingly insignificant changes that could be causing downstream disruptions along your network.
Another SolarWinds application designed to take troubleshooting busywork off your plate is Kiwi CatTools, a network automation tool designed to streamline your backup management processes, allow you to deploy bulk configuration changes simultaneously across groups of devices, and generate and deliver regularly scheduled reports. The licensing cost of Kiwi CatTools is based on the number of devices the application is installed on, making it an affordable option for smaller businesses that don’t need an enterprise-level network troubleshooting solution.
The Datadog product is modular and includes several useful applications. The first is Datadog Network Performance Monitor, a cloud-based traffic analytics program designed to provide down-to-the-second data on your network activity. Once the Datadog agent is installed on the monitored network, it can be configured to provide quick visibility into on-premises and cloud-based traffic, giving you valuable insights into how traffic is moving across the network.
Datadog Network Performance Monitor aggregates IP and port-level connection data from source and destination endpoints for further analysis while generating easy-to-understand graphic and visual representations. By analyzing flow data and tracking key network and server metrics, Datadog Network Performance Monitor can help to identify latent and previously undetected service dependencies and in troubleshooting DNS server issues. It’s an ideal tool for managing complex networks and provides built-in support for Linux and Windows operating systems.
One thing to note about Datadog tools is they’re named a little differently than other comparable network troubleshooting software. In this case, the functions typically carried out by a “network performance monitor” application are fulfilled by Datadog Network Device Monitor. The application gives visibility across your system environment, allowing you to monitor the performance of your applications, hardware, and DNS performance from the same dash, enabling easier cross-stack correlation and improved troubleshooting times.
This is another cloud-based application; once configured, the agent auto-discovers devices across the network and begins collecting valuable performance metrics like bandwidth, throughput, and others. These metrics can be easily graphed within the Datadog dashboard or used to create monitors to notify you when metrics reach critical performance thresholds.
Much like how the SolarWinds applications work well in concert, the two Datadog applications offer complementary services capable of powerful analysis and valuable network troubleshooting insights with live network topology mapping and statistics.
An ideal solution for complex networks, ManageEngine incorporates automation into many of its routine operations, streamlining your performance analysis and application monitoring processes. Designed for team-based infrastructure and multi-vendor networks, ManageEngine Network Configuration Monitor allows you to manage the configurations for your switches, firewalls, routers, and other devices all from one centralized console.
The tool automatically backs up configuration changes and conducts sweeps for signs of unauthorized updates or deviations, which can often give you an idea of where to start when it’s time to troubleshoot. The software makes it easy to quickly revert to previously approved configuration restore points—keeping your impact on system performance to a minimum—and logs user activity, while allowing you to revoke account privileges instantly if anything seems suspicious.
Another reason ManageEngine Network Configuration Monitor is a good choice for large networks is it includes a fully integrated patch manager designed to ensure network hardware and devices stay up to date on firmware, patch, and security updates as they’re released. This simplifies the amount of updating you have to handle manually, freeing you to attend to more important tasks.
Free Network Troubleshooting Tools to Know
As far as free tools or methods go,ping and tracerthave both been mentioned. They’re both well-known because they’re simple, easy to use, and can provide you with valuable information quickly.
Ping is simply a connectivity application baked into most operating systems that allows you to check if you’re able to create a network connection to a remote device or system. Ping operates by sending ICMP packets and waiting for the remote system to send them back—a simple way to check whether the remote system is responding. One useful aspect of the tool is, so long as you have the IP address or hostname, you can ping any other device using TCP/IP.
Tracert, rather than sending and waiting for packets, tracks the hops between the two hosts, collecting data about the network devices and their performance as it goes. This is an extremely useful tool in diagnosing and pinpointing your network routing issues.
If you only need to know the IP addresses of the devices you’re working on, then Ipconfig (Windows) and Ifconfig (Linux and Unix) should be your go-to. These will provide:
- IPv4 addresses
- IPv6 addresses
- MAC addresses
- DNS servers
- Default gateways and data
- Data about network traffic, errors, and dropped packets
Likewise, if you want to check which ports are open and listening on a host device, then netstat is another useful command line prompt to know, especially when you’re working with servers or hosts with their own firewalls in place (like SQL Server and Apache). This also provides network protocol statistics and lets you know who else is connected to your host and on which ports.
Start Streamlining Your Network Troubleshooting Practices Today
Using the right tool is the best way to ensure you’re monitoring for changes that could be creating issues, as you gain live performance data to inform your network troubleshooting approach. If you’re having trouble choosing the best solution, start with a free trial of a SolarWinds product. Network Performance Monitor offers a 30-day free trial for more comprehensive troubleshooting features, while Network Configuration Manager’s 30-day free trial is an excellent option for troubleshooting focused on device settings. For smaller businesses, consider Kiwi CatTools, which offers a 14-day free trial of its useful network automation features.