Hide an Admin User on Cisco IOS (Router/Switch) Platform [A How-To Guide]

Cisco EEM is a programming language built into any modern Cisco IOS switch or router. It allows for all sorts of automatic actions to take place. It also allows a key feature which we’ll exploit here — it can ‘catch’ a string a user enters and transparently replace it with another. This is messy programming, and allows many opportunities to cripple a router and confuse admins. The local log of the device will have many hidden lines in its buffer, so it will look short to someone looking closely.