How I Troubleshooted a VPN Latency Issue at Work: A Practical Approach

Introduction As an IT Infrastructure professional, network latency can be one of the most frustrating issues to troubleshoot, especially when it affects VPN connections that remote employees rely on. In this post, I want to share a real-world problem I faced at work and how I solved it.

The Issue: One morning, several employees reported slow VPN performance and intermittent disconnects. The VPN gateway was functioning, but users were experiencing 2-3 second delays when accessing internal services.

Investigation Process:

1. Checked the Obvious: • Verified that the VPN server was online. • Checked bandwidth utilization → It was within normal limits.

2. Checked Logs: • The VPN logs showed frequent rekeying and session drops. • Firewall logs indicated no packet drops.

3. Ran Network Diagnostics: • Ping to internal resources showed high latency (~150ms). • Trace route revealed delays at the ISP level.

The Root Cause: After engaging with the ISP, we found that one of their peering connections was degraded, causing packet loss on the path to our datacenter.
The Solution:

• ISP re-routed traffic through a healthy route.

• Users immediately reported improved VPN performance.

• Latency dropped from 150ms to 15ms.

Lessons Learned: • Always start troubleshooting from the network layer. • Don’t assume internal systems are always the cause. • Maintain a good relationship with your ISP for faster resolutions.

Conclusion: Troubleshooting network issues is a blend of experience, patience, and communication. I hope this story helps others facing similar workplace challenges.