OSPF supports two authentication methods: regional authentication and interface authentication. If these two authentication methods are configured at the same time, interface authentication is…

Question

Options

• ATRUE
• BFALSE

• A
  79% (33)
• B
  21% (9)

Explanation

Option A (TRUE) is correct because OSPF follows the principle of most-specific configuration wins: interface-level authentication is applied at a more granular scope than area (regional) authentication, so when both are configured on the same interface, the interface setting overrides the area-wide setting.

This behavior is consistent across major vendor implementations (Cisco, Huawei, etc.) - the interface authentication key and type will be used for neighbor adjacency formation, regardless of what the area authentication directive specifies.

Option B is wrong because ignoring the interface setting in favor of the area setting would make interface-level configuration pointless - the entire purpose of per-interface authentication is to allow exceptions to or overrides of the area-wide policy.

Memory tip: Think of it like CSS specificity - a rule applied to a specific element (interface) always beats a rule applied to a region (area). More specific = higher priority.

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