Networking

Sometimes you just need valid-looking MAC addresses for documentation, test data, configs, or mock environments — not for changing real hardware addresses or spoofing interfaces.

This method is platform-agnostic and works on macOS, FreeBSD, Linux, and most Unix-like systems with OpenSSL installed.

Generate with a one-liner in terminal

You can generate a properly formatted 48-bit MAC address using standard shell tools:

# Generate a random MAC address (locally-administered, unicast)
openssl rand -hex 6 | sed 's/$begin:math:text$\.\.$end:math:text$/\1:/g; s/.$//'

This walkthrough documents the cleanest recovery path for Netgate appliances running pfSense CE or pfSense Plus using a MacBook and the serial console this way we may avoid config loss, performing a factory reset, or a whipe/reinstall.

This is written as a practical runbook you can keep around for the next time someone locks themselves out.

What This Fixes (and What It Doesn’t)

This procedure:

• Resets the admin webConfigurator password
• Preserves your full pfSense configuration
• Works even if the web UI is unreachable

This does not: