norypt-router — GL-E750 Mudi Privacy Package

Privacy and anonymity enhancements for the GL-E750 / Mudi 4G mobile wi-fi router.

Features:

• IMEI randomization (via physical toggle, CLI, or web UI)
• BSSID randomization on every boot
• WAN MAC address randomization on every boot
• Persistent MAC address log wiping

Compatible with GL-E750 firmware 4.3.8 – 4.3.26 · MCU version ≥ 1.0.7 required

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Repository Layout

norypt-router/            ← OpenWrt package source (Makefile, files/, docs)
norypt_router_install/    ← Offline installer bundle (.ipk files + install.sh)

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Installation

Requirements

• GL-E750 / GL-E750V2 (Mudi) router with supported firmware
• A computer connected to the Mudi via WiFi or LAN
• SSH access to the router (default: root@192.168.8.1)

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Step 1 — Download the installer bundle

Clone or download this repository to your computer.

git clone <this-repo-url>

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Step 2 — Copy the installer bundle to the Mudi

Run the following command on your computer (not inside the router SSH session):

scp -O -r norypt_router_install root@192.168.8.1:/tmp

The -O flag is required on some systems due to the SSH daemon used by the Mudi.

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Step 3 — Connect to the Mudi via SSH

ssh root@192.168.8.1

Default password is printed on the device label, or previously set via the web interface.

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Step 4 — Run the installer

cd /tmp/norypt_router_install
chmod +x install.sh
./install.sh

The installer will:

1. Detect your firmware version
2. Install all bundled dependencies (no internet connection required)
3. Install the norypt-router package
4. Prompt you to reboot

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Step 5 — Reboot

When prompted, confirm reboot or run manually:

reboot

All features (BSSID randomization, MAC log wiping, WAN MAC randomization) activate automatically after reboot.

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Upgrading

Repeat Steps 2–5 with the new package. The installer uses --force-reinstall — safe to run on top of an existing installation.

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How to Change the IMEI (Physical Toggle — Step by Step)

This is the recommended method for maximum operational security. The full process uses the left hardware button on the Mudi device and the OLED display.

Before you start

Have your new SIM card ready before beginning. Once you start the process the modem radio is disabled — you will have no mobile connectivity until the process is complete.

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Stage 1 — Initiate the IMEI change

1. Hold / keep the left button in the DOWN position.
2. Push the button UP (flip the toggle switch to the upper / ON position).
3. The IMEI change sequence starts immediately.
4. Watch the OLED display — it will show progress messages:
   • Modem radio is disabled
   • An interim randomized IMEI is written (so the old IMEI is no longer active)
   • The display will show a prompt asking you to swap your SIM card

If the display goes dark for a few seconds, wait — the device is processing. The message will reappear. Do not move the switch until you see the SIM swap prompt.

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Stage 2 — Swap SIM and finalize

5. Remove your old SIM card and insert the new SIM card now.
6. Once the new SIM is seated, push the button back DOWN (toggle switch to the lower / OFF position).
7. The device will:
   • Write the new randomized IMEI
   • Power off automatically

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After the process

8. Do not power on immediately — first change your physical location. Moving before your next boot ensures the device connects to different cell towers than those that served the old SIM/IMEI combination, breaking the geographic link between old and new identities.
9. Once you are in the new location, power on the device normally.
10. The new IMEI and new SIM are now active.

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Summary (quick reference)

Step	Action	What happens
1	Button UP (toggle ON)	IMEI change sequence starts, modem radio off
2	Watch OLED	Progress shown; wait for SIM swap prompt
3	Swap SIM card	Replace old SIM with new SIM
4	Button DOWN (toggle OFF)	New IMEI written, device powers off
5	Change location	Move before next boot
6	Power on	Device boots with new SIM + new IMEI

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Alternative Methods to Change IMEI

CLI (SSH)

ssh root@192.168.8.1
norypt-router

Follow the on-screen prompts. Reboot after completion. Change location before next boot.

Web UI (LuCI)

1. Open the Mudi web interface in a browser
2. Go to System → Advanced Settings → LuCI
3. Navigate to Network → Norypt Router
4. Press SIM swap... to begin
5. Shut down the device, swap the SIM, change location, then boot

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Security Notes

• Always change location after swapping IMEI and SIM — connecting to the same towers with a new identity still allows correlation by tower logs.
• The device radio is turned off before any IMEI change to prevent the old IMEI from leaking during the transition.
• BSSID and WAN MAC are randomized automatically on every boot — no manual action needed.
• The persistent client MAC address log is shredded and moved to RAM on every boot.

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Troubleshooting

Problem	Solution
/dev/ttyUSB3 does not exist	Reboot. If persistent, reseat the modem module.
IMEI did not change after process	Full power cycle: shut down, wait 10 s, power on.
install.sh: permission denied	Run chmod +x install.sh first.
OLED goes blank mid-process	Wait up to 1 minute — device is still working.
No message after 1 minute	Pull switch to restart the process from the beginning.

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Building from Source

See norypt-router/README.md for full build instructions using the OpenWrt build system.

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License

See norypt-router/LICENSE.md.