Kevin Veen-Birkenbach
10522d591a
- Added main.py: automatic WireGuard MTU calculation and PMTU probing - Added test.py: unittests covering base, PMTU, and fallback scenarios - Added Makefile: includes test target and install guidance - Added README.md: usage, pkgmgr installation, and MIT license Reference: https://chatgpt.com/share/68efc179-1a10-800f-9656-1e8731b40546
2.3 KiB
2.3 KiB
wg-mtu-auto
Automatically detect the optimal WireGuard MTU by analyzing your local egress interface and optionally probing the Path MTU (PMTU) to one or more remote hosts.
The tool ensures stable and efficient VPN connections by preventing fragmentation and latency caused by mismatched MTU settings.
✨ Features
- Automatic Egress Detection — Finds your primary internet interface automatically.
- WireGuard MTU Calculation — Computes
wg0MTU based on egress MTU minus overhead (default 80 bytes). - Optional Path MTU Probing — Uses ICMP “Don’t Fragment” (
ping -M do) to find the real usable MTU across network paths. - Multi-Target PMTU Support — Test multiple remote hosts and choose an effective value via policy (
min,median,max). - Dry-Run Mode — Simulate changes without applying them.
- Safe for Automation — Integrates well with WireGuard systemd services or Ansible setups.
🚀 Installation
Option 1 — Using pkgmgr
If you use Kevin Veen-Birkenbach’s package manager (pkgmgr):
pkgmgr install automtu
This will automatically fetch and install wg-mtu-auto system-wide.
Option 2 — Run directly from source
Clone this repository and execute the script manually:
git clone https://github.com/kevinveenbirkenbach/wg-mtu-auto.git
cd wg-mtu-auto
sudo python3 main.py --help
🧩 Usage Examples
Basic detection (no PMTU)
sudo automtu
Specify egress interface and force MTU
sudo automtu --egress-if eth0 --force-egress-mtu 1452
Probe multiple PMTU targets (safe policy: min)
sudo automtu --pmtu-target 46.4.224.77 --pmtu-target 2a01:4f8:2201:4695::2
Choose median or max policy
sudo automtu --pmtu-target 46.4.224.77,1.1.1.1 --pmtu-policy median
sudo automtu --pmtu-target 46.4.224.77,1.1.1.1 --pmtu-policy max
Dry-run (no system changes)
automtu --dry-run
🧪 Development
Run unit tests using:
make test
To see installation guidance (does not install anything):
make install
👤 Author
Kevin Veen-Birkenbach https://www.veen.world