100-160 · Question #44
Which security measure can prevent unauthorized devices from automatically connecting to a corporate network through unused switch ports?
The correct answer is A. Port security. Port security can prevent unauthorized access by limiting or specifying the MAC addresses allowed to connect through a given switch port. This mitigates risks from rogue devices connecting to the network.
Question
Which security measure can prevent unauthorized devices from automatically connecting to a corporate network through unused switch ports?
Options
- APort security
- BVLAN trunking
- CNAT
- DVPN
How the community answered
(62 responses)- A95% (59)
- B2% (1)
- C3% (2)
Explanation
Port security can prevent unauthorized access by limiting or specifying the MAC addresses allowed to connect through a given switch port. This mitigates risks from rogue devices connecting to the network.
Topics
Community Discussion
3
Samuel O.Nov 18, 2025Port security is the answer, and once you have seen it in the field it becomes one of those things you never forget. The feature lets you lock a switch port to a specific MAC address or a set number of addresses, so if something you did not authorize plugs in, the port shuts down or drops the traffic outright. The other options are doing completely different jobs, NAT translates addresses between networks, VPN creates encrypted tunnels for remote access, and VLAN trunking carries multiple VLANs across a link. None of those have any mechanism to say "I do not recognize this device, you are not getting in" at the physical port level the way port security does.
Fatima Z.Nov 13, 2025Port security is your answer, and here is the sticky hook to lock it in: think "PORT BOUNCER" because just like a club bouncer checks your ID at the door, port security checks a device's MAC address before letting it onto the network, and if you are not on the list, you are not getting in. The unused ports can be shut down or limited to zero allowed MACs, so a rogue laptop cannot just plug in and party on your corporate LAN.
Carlos M.Nov 9, 2025Kept thinking VPN but port security literally locks unused ports to specific MACs.