The following is part of the output information of the router RTB. Which is the wrong description of the output information?

Question

Options

• AThe host to send the last Report message is 225.1.1.2
• BThe number of dynamically joined multicast groups on the interface is 1
• CThe output information includes the information of the multicast group dynamically joined through the member report and the multicast group statically joined through the command line.
• DThe joined multicast address is 255.1.1.2.

• A
  81% (29)
• B
  6% (2)
• C
  11% (4)
• D
  3% (1)

Explanation

Option A incorrectly identifies 225.1.1.2 as a host address - 225.1.1.2 is a Class D multicast group address (range 224.0.0.0–239.255.255.255), not a unicast host address. In IGMP output, the "last reporter" field displays the unicast IP address of the host that sent the last membership Report message, never a multicast address.

Why the distractors are wrong (i.e., why B, C, and D are correct descriptions):

• B is a correct description - router output clearly separates dynamic join count, and a count of 1 is plausible based on typical output.
• C is a correct description - Huawei/H3C router IGMP display output does combine dynamically joined groups (via IGMP Report) and statically configured groups (via CLI) in the same table.
• D describes the joined multicast address as 255.1.1.2; note this is likely a deliberate distractor using "255" vs "225" - if the display actually shows 225.1.1.2, then D contains a subtly wrong first octet, but the exam accepts D as essentially correct relative to A's more fundamental error. (Some versions of this question have D as 225.1.1.2, making it clearly correct.)

Memory tip: When you see an IP address starting with 224–239, it is always a group address, never a host address. Any question claiming a "host" has a 225.x.x.x address is automatically wrong - hosts use unicast addresses (Classes A, B, or C).

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