By default, the Level of the IS-IS router interface is 1evel-2.

Question

Options

• ATRUE
• BFALSE
• C
• D

• A
  10% (2)
• B
  81% (17)
• C
  5% (1)
• D
  5% (1)

Explanation

Option B (FALSE) is correct because IS-IS router interfaces default to Level 1-2, not Level 2 alone - meaning they participate in both Level 1 (intra-area) and Level 2 (inter-area) adjacencies unless explicitly restricted. Option A is wrong because it accepts the false premise that the default is Level 2 only; this is a common trap since Level 2 handles backbone/inter-area routing and may seem like a "default" choice. Options C and D are blank distractors with no content to evaluate.

Memory tip: Think "IS-IS interfaces speak both languages by default (L1 + L2) - you have to silence one deliberately." If a vendor asks you to restrict to a single level, that's always an explicit config step, never the default.

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