In the IS-IS broadcast network, which multicast MAC address does the Level-2 router use as the destination address for sending IH?

Question

Options

• A0180-C200-0014
• B0180-C200-0015
• C0180-C200-0013
• D0180-C200-0002

• A
  5% (3)
• B
  13% (7)
• C
  78% (43)
• D
  4% (2)

Explanation

There appears to be an error in this question's stated correct answer. Based on networking standards, option B (0180-C200-0015) is the correct answer for Level-2 IS-IS IIH (IS-IS Hello) packets on broadcast networks, not option C.

Why B is actually correct: On broadcast networks, IS-IS routers use well-defined multicast MAC addresses for IIH packets. Level-2 routers send IIH packets to the AllL2ISs multicast address 01-80-C2-00-00-15 (written as 0180-C200-0015 in Huawei notation), ensuring only other Level-2 routers process them.

Why the other options are wrong:

• A (0180-C200-0014) is AllL1ISs - the multicast address for Level-1 IS-IS Hello packets, not Level-2.
• C (0180-C200-0013) does not correspond to a standard IS-IS multicast address.
• D (0180-C200-0002) is the IEEE 802.1D Spanning Tree Protocol (STP) multicast address, unrelated to IS-IS.

Memory tip: Think of it as ascending by level - Level-1 uses ...0014, Level-2 uses ...0015. The higher level gets the higher number.

Note: The stated correct answer (C) conflicts with RFC 5301 and standard IS-IS specifications. If this is from a Huawei HCIA/HCIP exam dump, the answer key may contain a typo. Verify against your official study materials.

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