Determine ISP Password from Netcomm Routers
If you have lost or forgotten your ISP password, you cannot view it in your router's user interface as they are usually hidden. However the router needs to store the password in plain text in order to connect to the ISP. Some routers will expose the password in plaintext if you save the settings of the router to a file. Others, such as some Netcomm models, obscure the password in the saved configuration file.
To determine the password:
- Save the settings of the router to a file.
- Open the file (probably backupsettings.xml).
- Search for a line such as:
- The obscured password value is calculated by subtracting the ASCII value of each character from 255, then converting the result to a two-character hexadecimal value.
So in the above example, the string is 18 characters long, the password is therefore 9 characters long.
The first character is represented by 98, which is 152 in decimal. 255 minus 152 = 103. The ASCII character represented by 103 is g, which is thus the first character of the password. Continue for the remainder of the characters.
To use Microsoft Excel to decode the string:
- Place the 2-character hexademical numbers in a column, say A1..A9.
- Formula for B1 is:
- Copy this formula down the B column.
The results spell out the password.