Troubleshooting Network Connectivity

Troubleshooting Network Connectivity: An Overview

• Troubleshooting network connectivity is a crucial skill for IT professionals, especially at the helpdesk level.
• This involves diagnosing and resolving network issues for both wired and wireless users, whether local or remote.
• The aim is to equip IT professionals with the knowledge and tools to efficiently tackle connectivity problems.

Approaching Wired Network Issues

• When dealing with wired clients, IT professionals often receive notifications about connectivity problems from co-workers or through help desk tickets.
• A primary troubleshooting step is to ensure that the network cable is securely plugged into both the computer and the network port.
• It's important to visually inspect cable connections, understanding that physical limitations may require the IT professional to check connections directly.

Understanding Network Cable LEDs

• Network cables need to be inspected for damage from general wear and tear.
• LEDs on computer equipment are valuable indicators for technicians.
• On network cards, a solid LED typically indicates link status, while a flashing LED signifies Ethernet traffic.
• The link LED may use different colors to indicate connection speed (e.g., green for 10 Mbps, amber for 100 Mbps, yellow for 1 Gbps).
• Enterprise switches also have link and activity LEDs to show connections.

Link Light Functionality

• The link LED indicates a stable layer one connection, resulting from auto-negotiation between the network card and the switch.
• The network card is responsible for establishing and maintaining the link lights on both the switch port and the card.
• Failure to negotiate speed or duplex will result in the link light remaining off.
• The link light will also be off if either the network card or switch is powered off, being reset, or reinitialized.

Remote Diagnostics Using PowerShell

• Before physically going to a user's location, IT professionals should attempt to remotely connect to the PC.
• PowerShell can be used to test the connection using the Test-Connection command, verifying connectivity through various layers.
• This test is valuable for confirming a connectivity issue before escalating the troubleshooting process.

Basic Troubleshooting for Wireless Users

• Basic wireless troubleshooting involves confirming that Wi-Fi is enabled and airplane mode is disabled.
• Users should verify that they are connected to a trusted access point (Wi-Fi network).
• Disconnecting and reconnecting to the network can sometimes resolve connectivity issues.
• Attempting to connect to a different frequency band (e.g., 2.4 GHz instead of 5 GHz) of the same trusted access point.

Portable Tools for Network Troubleshooting

• Specialized tools like the LinkRunner AT 1000 (now under NetAlly) are designed for network connectivity troubleshooting.
• These tools offer functionalities like switch port identification, VLAN information, link speed/duplex verification, cable testing, and PoE testing.
• Alternative tools are available at various price points, offering more affordable solutions for network testing needs and connecting directly to your phone.

Addressing Browser-Related Issues and Malware

• If network connectivity tests pass but the user still cannot access the internet via a browser, try an alternate browser to rule out browser-specific issues.
• Malware and viruses can cause network connectivity problems, requiring a scan for infections.
• Expired antivirus products can sometimes block web traffic, necessitating their removal.

Advanced Troubleshooting Steps in Windows 10

• Launch the built-in network troubleshooter via Start > Settings > Network & Internet > Network troubleshooter.
• Alternatively, advanced users can manually run commands like netsh winsock reset, netsh int ip reset, ipconfig /release, ipconfig /renew, and ipconfig /flushdns in PowerShell.
• The network troubleshooter can also be launched from the command line using the command msdt.exe -id NetworkDiagnosticsNetworkAdapter.

Router and Modem Troubleshooting

• If connectivity issues persist, rebooting the router is a common troubleshooting step- Unplug the power cable from the router and modem, wait 30 seconds, and then plug it back in.
• You may need to disengage the battery
• Understand your ISP modems LED lights, and take a picture of your ISP modem so you know what the lights look like when everything is good.
• For business environments, document the LED status of ISP-provided equipment to effectively communicate with the ISP's technical support.

Network Card Driver Reinstallation and Network Reset

• Uninstalling and reinstalling the network card driver can resolve driver-related issues.
• In Device Manager, uninstall the network adapter and then scan for hardware changes to reinstall the driver automatically.
• As a last resort, use the Network Reset option in Windows 10 (Start > Settings > Network & Internet > Network reset) to reset all network settings. However, be cautious as this can affect VPN software and other network configurations.

Portable Internet Repair Tool

• The Internet Repair tool is a portable app that can address many network connectivity issues, make sure you create a system restore point on your PC before starting this process.
• Start by using the most minimal tools and working your way down.

Addressing Wireless Interference

• Wireless interference is a major factor in slow or unreliable wireless connections.
• Common sources of interference include microwave ovens, cordless phones, and other electronic devices.
• Physical barriers like concrete walls can also weaken wireless signals.
• USB 3.1 devices and cables can interfere with wireless signals if poorly shielded.
• Use tools like the Microsoft Wireless Report to analyze wireless network performance and identify potential issues.
• Ensure you analyze your wireless report

Internet Speed Testing Tools

• DSLReports.com is good for verifying PC functionality and features multiple servers for accurate throughput testing.
• Fast.com, powered by Netflix, is useful for testing video upload and download speeds.
• TestMy.net provides accurate upload, download, and latency tests.
• Speedtest.net accurately measures network connectivity and returns download, upload, and latency speeds.