Huawei Certified Network Associate – Routing and Switching (HCNA-RS, legacy) — Question 75

Which of the following statements are true about the blackhole MAC address table?

Answer options

• A. Entries are manually configured and delivered to each interface card. The entries cannot be aged out.
• B. After a device is reset, an interface card is hot swapped, or an interface card is reset, the saved entries on the device or interface card are not lost.
• C. After a blackhole MAC address is configured on a device, the device discards packets whose source or destination MAC address is the blackhole MAC address.
• D. Blackhole MAC address entries can be used to filter out unauthorized users.

Correct answer: C

Explanation

Option C is correct because once a blackhole MAC address is configured, the device indeed drops packets with that MAC address. The other options are incorrect: A is wrong because entries can age out, B is false as entries can be lost after a reset, and D is misleading since blackhole MAC addresses are specifically for dropping packets, not for user filtering.