This combination begins with an escape character that signals the receiving system to interpret the following bytes as a command instead of literal text. Hardware interfaces and terminal emulators rely on these sequences to manipulate cursor position, change text colors, or interrupt active processes. In networking equipment, a specific sequence often drops an administrator out of an active telnet or SSH session back to the local command prompt.
Heard on the job
If the router console hangs during boot, hit the escape sequence to break into ROM monitor mode.
Insider tip
The most famous escape sequence in networking is Cisco's Ctrl-Shift-6, which aborts DNS lookups and ping sweeps.