ISE vs a ethernet y cable splitter

[mcmanus]

In my corporate environment, IT won't give permission for a switch, they wants us to lay more cable, but it's too expensive.  Leadership doesn't understand and says just use WiFi.  ISE of course prevents using a switch without permission; ISE will detect it and quarantine it.  But would 2 computers hooked up to a y splitter cable get quarantined?  My understanding is that rogue switches get blocked because they are not configured correctly and are not secure.  BUt, a y cable has o such issues?

[Marvin Rhoads]

A splitter cable will not allow 3 devices (2 computers and a switch port) to communicate at all, much less with ISE. Switched Ethernet just doesn't work that way.

When multiple devices are connected to a switch port (either with a downstream unauthorized hub or a phone with a PC connected, etc.) the switch configured with ISE as the RADIUS server for dot1x authorization control will detect the multiple MAC addresses and behave according to the configured policy (authenticate each separately, authenticate only one data and one voice domain device, block all bu the first connected address, etc.)