LAN mapping table is an attribute of the IST domain and is used to describe the mapping relationship between VLAN and MSTI. Each VLAN can correspond to multiple MSTIs, and one MSTI can correspond to…

Question

Options

• ATRUE
• BFALSE

• A
  20% (10)
• B
  80% (40)

Explanation

B is correct because the statement contains a critical error: in MSTP (Multiple Spanning Tree Protocol), each VLAN can only map to one MSTI - not multiple. The relationship is many-to-one from VLANs to MSTIs (many VLANs → one MSTI), never one-to-many. Additionally, the VLAN mapping table is an attribute of the MST region, not specifically the IST domain; the IST (MSTI 0) is itself just one spanning tree instance within that region, responsible for carrying unassigned VLANs and inter-region traffic.

Why A is wrong: Accepting the statement as true would mean a single VLAN could participate in multiple spanning tree topologies simultaneously, which MSTP explicitly prohibits - a VLAN can only follow one active forwarding path per region.

Memory tip: Think "one VLAN, one home." Each VLAN is assigned to exactly one MSTI (its home), but a single MSTI can house many VLANs - like many residents sharing one house, but no resident can live in two houses at once.

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