How to troubleshoot and fix slow VPN connection speeds

Network & Internet KB-397

Summary

This guide helps you troubleshoot and resolve: How to troubleshoot and fix slow VPN connection speeds. Follow the steps below to fix the issue.

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Common Causes

Experiencing slow speeds or high latency while connected to your VPN can disrupt your workflow and make cloud-based applications feel unresponsive. Because a VPN encrypts your data and routes it through a secure server, some performance dip is normal; however, significant slowdowns usually indicate a configuration issue or a local network bottleneck.

Quick Fix Steps

Before diving into deep technical troubleshooting, try these rapid solutions to rule out common glitches:

Restart your equipment: Power cycle your modem, router, and computer.
Toggle the VPN: Disconnect from the VPN, wait ten seconds, and reconnect.
Check your internet: Disconnect the VPN and run a speed test to ensure your base NBN or 5G connection is performing as expected.
Switch your connection: If you are using Wi-Fi, try connecting via an Ethernet cable to rule out wireless interference.

Detailed Instructions for Performance Optimisation

Optimising your local network

Your home or office network environment heavily impacts VPN stability. If your local signal is weak, the encrypted tunnel will struggle to maintain speed.

Ensure you are following the best practices in our guide on How to connect to Wi-Fi to ensure a stable wireless signal.
Move closer to your wireless access point or router.
Disconnect other high-bandwidth devices (such as gaming consoles or streaming TVs) on your network that may be consuming your available bandwidth.

Adjusting VPN Client Settings

Depending on the VPN software your organisation uses, certain settings can be tweaked to improve throughput.

Change the Protocol: If your client allows it, switch between UDP (faster, better for video calls) and TCP (more stable, better for file transfers).
Update the Client: Ensure you are running the latest version of the VPN software. Check for updates in the Settings or About menu of the application.
Disable Split Tunneling (if applicable): Check with your administrator if Split Tunneling is enabled. This allows only business traffic to go through the VPN while your general web browsing stays on your local connection, significantly increasing speed.

Pro Tip: If you are using a laptop, ensure your power plan is set to Best Performance rather than Power Saver, as some network adapters throttle speed to save battery.

Troubleshooting Advanced Issues

Analysing DNS and Latency

Sometimes the slowdown isn't the speed of the data transfer, but the time it takes for the server to respond (latency).

Open the Command Prompt (Windows) or Terminal (macOS).
Type ping google.com and press Enter.
Note the time=XXms value.
Connect to your VPN and run the same command.
If the latency increases by more than 100ms, the issue may be related to the VPN server's current load or your routing path.

Checking for Software Conflicts

Third-party security software can sometimes "double-scan" encrypted VPN traffic, causing a bottleneck.

Firewalls: Ensure your local firewall allows the VPN application to communicate through the necessary ports.
Antivirus: Temporarily disable your antivirus "Web Shield" or "Network Inspection" feature to see if speeds improve.

Caution: Do not disable your firewall or antivirus permanently. Only disable them briefly for testing purposes to identify the cause of the slowdown.

If you have followed these steps and your connection remains slow, please Open a Ticket so our engineers can analyse your connection logs and server performance.

Still Having Issues?

Need more help? If the issue persists after trying these steps, please open a support ticket and our team will assist you.

💻 Open a Ticket