IPA IP 2021 Question 85
A question IPA Japan published in 令和3年度 ITパスポート試験 公開問題 問85, translated into English. ITPEC is based on the same exams.
In the security of a wireless LAN, which of the following is a mechanism with which, when an access point receives a connection request from a terminal such as a PC, it restricts connection on the basis of information unique to the terminal that has requested the connection?
Explanation
MAC address filtering — the access point lets a terminal connect only if the MAC address it presents is on the list of permitted terminals.
A MAC address is assigned to each network interface by its manufacturer, so it identifies the terminal itself. With MAC address filtering the access point holds a list of the MAC addresses allowed to connect and refuses connection requests from any other terminal. It is information unique to the requesting terminal, which is what the question describes. On its own it is weak, since MAC addresses can be read off the air and spoofed, so it is combined with encryption such as WPA2.
Answer (b)
Why not others:
- •(a) ESSID — the name that identifies a wireless network; terminals specify it to choose a network, and it says nothing about which terminal is asking
- •(c) VPN — a virtual private network over a public network, protected by encryption and tunnelling; not a connection check at the access point
- •(d) WPA2 — a security standard that encrypts wireless traffic and authenticates users with a pre-shared key or IEEE 802.1X, not by the terminal's own identifier
Key rule: A terminal's unique hardware identifier on a LAN is its MAC address; an access point that admits terminals by that address is doing MAC address filtering.
Security · AI-written, may contain errors
This question comes from the past questions IPA Japan publishes, translated into English by ITPEC Practice. ITPEC Practice is an independent study tool and is not affiliated with IPA or ITPEC. See the original paper (PDF) or Report an issue.