Apparently, these chips emulate or bypass an I2C EEPROM containing part of the code executed during the boot sequence, and Cisco depends on this EEPROM’s contents for authenticity verification.

A common I2C EEPROM – you likely have a good few such chips within a dozen meter radius. By [Raimond Spekking], CC BY-SA 4.0 I2C is a two-wire interface, and you can put multiple devices on ...

I2C was created by Phillip Semiconductors in 1980 to reduce cost by simplifying the interface for connecting a central ...