How Your Multi-Layer Network Operates
From the cloud VPS to your local Windows 10 host and internal Kali Linux WSL2 sandbox over an MTU-clamped WireGuard Tailscale tunnel.
🔍 Contabo VPS Architecture Linux Host
Runs Tailscale node agent, SSH Client, 9Router, and Caddy reverse proxy. Direct connection established to Windows PC with MTU 1200 clamp.
The MTU Blackhole Bug
The direct IPv6 path between GrameenPhone 4G and the Contabo VPS had a max frame threshold of 1216 bytes. Tailscale defaulted to 1280 bytes, causing SSH key exchange (SSH2_MSG_KEX_ECDH_REPLY) to drop silently.
Windows 10 OpenSSH Bridge
Windows OpenSSH Server listens on 0.0.0.0:22. When commands are dispatched for Windows, they execute in PowerShell. When dispatched for Kali, they pipe through wsl.exe -d kali-linux.
Kali Linux (WSL2) Sandbox
WSL2 runs on an internal hypervisor switch (172.30.160.0/20). Nmap and network utilities run natively on Linux kernel 6.18 with access to Windows networking.