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How to Optimize OpenVPN MTU for 1Gbps Uplinks

Tune MSS, fragment, and tun-mtu parameters to eliminate throughput loss on OpenVPN tunnels over gigabit residential links.

VPN Configure Editorial Team

Networking Editorial

Published May 21, 2026Updated Jun 30, 2026

OpenVPN 2.5+

Overview

OpenVPN throughput on gigabit links is dominated by MTU related fragmentation. Tuning tun mtu, mssfix, and fragment brings a well provisioned tunnel within 5% of raw link speed.