I was staying in a hotel and connected to the wifi. I got one of those one-time login page when conecting. I forgot to put the promo code in. Then I got stuck with 4Mbit/s and not the faster promo speed. I wasn't able to return to the login page, nor was I able to bring it back up by clearing cookies, deleting the connection, using a different browser, etc. I suppose the hotel network remembers the device based on its MAC address which then makes you automatically bypass the login page.
The solution involves temporarily changing the device's MAC address. This makes the network treat the device as a new entity, thereby prompting the login page again.
- Ubunu 20.04
- Lenovo Thinkpad
- Wireless connection
Also worth noting that this is pretty much what is happening in the automated scripts that I have created below.
Open your terminal...
Identify your Wi-Fi network interface using ifconfig or ip link show. Then, disable it using: sudo ip link set dev [interface_name] down.
Replace [interface_name] with your actual Wi-Fi interface name. In my case it was wlp0s20f3.
Generate a new MAC address or use a specific one, then apply it: sudo ip link set dev [interface_name] address XX:XX:XX:XX:XX:XX.
General:
The maximum length of a MAC address is 17 characters. MAC addresses are composed of the following characters: "0-9", "a-f", "A-F", and ":". MAC addresses must be in the following format: xx:xx:xx:xx.
A MAC address consists of 48 bits, usually represented as a string of 12 hexadecimal digits (0 to 9, a to f, or A to F); these are often grouped into pairs separated by colons or dashes. For example, the MAC address 001B638445E6 may be given as 00:1b:63:84:45:e6 or as 00-1B-63-84-45-E6.
Advanced:
When setting randomly generated MAC addresses, I kept getting this error: RTNETLINK answers: Cannot assign requested address. I guess I should have done some more extensive reading on MAC addresses. Thank you GPT4.
"Understanding the significance of the bits in a MAC address is crucial for correctly setting a custom MAC address.
Multicast Bit: The least significant bit of the first byte of the MAC address is the multicast bit. If this bit is set to 1, the address is treated as a multicast address, which is not suitable for a device's unique identifier.
Local Assignment Bit: The second least significant bit in the first byte of the MAC address is the local assignment bit. When setting a custom MAC address, this bit should be set to 1 to indicate that the address is locally administered and not assigned by a hardware manufacturer.
In the example you provided (21:87:ac:b3:7d:66), the first byte 21 in binary is 00100001. Here, the multicast bit is 0 (which is correct), but the local assignment bit is also 0 (which should ideally be 1 for custom MAC addresses).
To correct this, you should ensure that the second least significant bit of the first byte is set to 1. For example, you could use 22:87:ac:b3:7d:66 or 26:87:ac:b3:7d:66 (where 22 and 26 in binary are 00100010 and 00100110, respectively, both having the local bit set to 1)."
Run: sudo ip link set dev [interface_name] up.
Run: ip link show [interface_name].
- This change is temporary. The MAC address reverts to its original state after a system reboot.
- If any issues arise, simply reboot your device to revert to the original MAC address.
- Displays all network interfaces along with their current MAC addresses.
- Allows you to choose the network interface you want to spoof.
- Automatically generates a random, valid MAC address.
To run: ./terminal_mac_spoofer.sh
- You will be asked for sudo privileges.
- You will be asked to specify which network interface you'd like to spoof.
- Done.
This is the easiest way to do it. I don't know if it's the most efficient. For example, what if your network device connects to the network somehow before this Job is executed. I haven't thought hard enough about this. Nevertheless...
- Store the spoofing script somewhere safe.
- Open your crontab file with the command:
crontab -e - In the crontab file, add the following line:
@reboot /path/to/mac_spoof.sh - Reboot and check by running:
ip link show [interface_name]. - Should be spoofed.
Install
- Zenity:
sudo apt-get install zenity- For Shell GUI
It's easy to use. Just run it and follow the instructions: ./gui_mac_spoofer.sh
- You can select a network interface from a list. I pick my wireless one.
- You can enter a specific MAC address or leave it blank for a random one.
- A progress bar shows the process of disabling, changing the MAC address, and re-enabling the network interface.
- You should see a confirmation message with the new MAC address.
I kept getting this error but eventually I got rid of it (GPT4 did actually..). See the MAC rules earlier in the readme. Hopefully it doesn't pop up again.