SK0-004 · Question #677
A user notices that when plugging a company-assigned laptop into a network port it is able to get an IP address via DHCP. However, when plugging a personal laptop into the same port, it does not get…
The correct answer is A. The company is using 802.1X port security. 802.1X is a network access control standard that requires devices to authenticate before being granted network access, which explains why the unauthenticated personal laptop is blocked while the corporate laptop passes.
Question
A user notices that when plugging a company-assigned laptop into a network port it is able to get an IP address via DHCP. However, when plugging a personal laptop into the same port, it does not get a valid IP address. Which of the following is the MOST likely cause of this?
Options
- AThe company is using 802.1X port security.
- BThe personal laptop is using an unsupported operating system.
- CThe network cable is only Cat 5e.
- DPort 53 is closed on the personal laptop.
How the community answered
(56 responses)- A70% (39)
- B4% (2)
- C7% (4)
- D20% (11)
Why each option
802.1X is a network access control standard that requires devices to authenticate before being granted network access, which explains why the unauthenticated personal laptop is blocked while the corporate laptop passes.
802.1X port-based Network Access Control (NAC) requires a supplicant (client) to present valid credentials - such as a certificate or username/password - to an authentication server (typically RADIUS) before the switch port is authorized. The company laptop has the required credentials or certificate configured, while the personal laptop does not, causing the switch to keep its port in an unauthorized state and block DHCP traffic.
Operating system support does not determine whether a switch port grants DHCP access; 802.1X authentication is OS-independent at the network level.
Cat 5e cable supports up to 1 Gbps and would affect both laptops equally; it would not selectively prevent one device from receiving a DHCP address.
Port 53 is the DNS port and has no role in obtaining an IP address via DHCP, which uses UDP ports 67 and 68.
Concept tested: 802.1X port-based network access control
Source: https://learn.microsoft.com/en-us/windows-server/networking/technologies/nap/nap-top
Topics
Community Discussion
No community discussion yet for this question.