Implementing and Operating Cisco Enterprise Network Core Technologies (ENCOR) v1.2SecurityHard
A network administrator is configuring 802.1X on a Cisco switch port connected to an IP phone, which then connects to a PC. The administrator wants both the IP phone and the PC to authenticate independently and receive appropriate network access. Which 802.1X feature should be enabled to support this scenario?
- AMulti-Domain Authentication (MDA)
- BGuest VLAN
- CSingle-Host Mode
- DMulti-Host Mode
Show answer & explanationAnswer & explanation
Correct answer: A. Multi-Domain Authentication (MDA)
Multi-Domain Authentication (MDA) is specifically designed for scenarios where a single port has multiple devices, typically an IP phone and a PC, and each device needs to authenticate independently to its respective VLAN (e.g., voice VLAN for phone, data VLAN for PC).
Why the other options are wrong
- B. Guest VLAN provides limited access for non-authenticated devices, not independent authentication for multiple devices.
- C. Single-Host Mode allows only one authenticated device per port.
- D. Multi-Host Mode allows multiple devices but authenticates only the first, granting access to all others.
802.1X Multi-Domain Authentication (MDA)
An 802.1X switch port mode that allows an IP phone and a single data device (like a PC) to authenticate separately on the same port.
- Supports both voice and data authentication on one port.
- IP phone authenticated to the voice VLAN, PC to the data VLAN.
- Requires separate MAC addresses for each device.
Memory trick: How many and who gets in through the 802.1X door?