Windows consistently very slow initial connection SSL (5 seconds)

Understanding and Resolving Slow Initial SSL Connections on Windows: A Guide for Troubleshooting Network Performance Issues

Introduction

Experiencing slow website loading times can be frustrating, especially when initial connections and SSL handshakes take several seconds. If you’re a Windows user facing consistent delays of around 4-5 seconds during the first attempt to access websites, this article aims to provide insights into possible causes and practical troubleshooting steps to improve your network performance.

Background Scenario

Many users encounter sudden network slowdowns following specific activities, such as large file uploads or changes in network configuration. For instance, a user recently experienced connection issues after uploading certain files, leading to errors accessing websites despite the network seeming functional on other devices like smartphones. Such incidents often point to underlying problems affecting DNS resolution, IP configuration, or SSL handshake processes.

Common Causes of Slow Initial SSL Handshake

1. IPv6-Related Delays
2. Some Windows configurations may attempt IPv6 connections first, which can introduce delays if IPv6 networking is improperly configured or unsupported by the network.

3. Disabling IPv6 can sometimes reduce connection latency for IPv4-dominant environments.

4. DNS Resolution Issues

5. Slow or misconfigured DNS can cause delays in translating domain names to IP addresses.

6. Flushing DNS cache or switching to more reliable DNS servers can help.

7. SSL Certificate Verification

8. Problems with SSL certificate validation, such as outdated or misconfigured certificates, can cause delays during handshake.

9. Ensuring your system date and time are correct and updating trusted certificates may resolve such issues.

10. Network Interference or Factory Settings

11. Driver issues, firewall settings, or network interference can also contribute to connection delays.

Troubleshooting Steps

1. Disable IPv6
2. Navigate to Network Settings > Adapter Options.
3. Right-click your active network connection > Properties.
4. Uncheck “Internet Protocol Version 6 (TCP/IPv6).”

5. Save settings and restart your browser or system to see if connections improve.

6. Flush DNS Cache

7. Open Command Prompt as administrator.
8. Run the command: ipconfig /flushdns

9. Restart your browser or network applications to test improvements.

10. Change DNS Servers

11. Consider switching to public DNS providers like Google DNS (8.8.8.8 & 8.8.4.4) or Cloudflare (1.1.1.1).
12. Adjust DNS