When using system routes and user defined routes in Azure, which takes precedent?

Question

Options

• AThe user defined route takes precedent
• BThe system route always takes precedent
• CThe most specific route takes precedent
• DThe newest route takes precedent

• A
  5% (3)
• B
  2% (1)
• C
  87% (52)
• D
  7% (4)

Explanation

Azure routing uses longest prefix match - whichever route has the most specific destination (longest subnet mask) wins, regardless of whether it's a system route or a user-defined route (UDR). For example, a UDR for 10.0.1.0/24 overrides a system route for 10.0.0.0/8 for traffic destined to that subnet, simply because /24 is more specific.

Why the distractors are wrong:

• A - UDRs don't win by default just because they're user-defined; a system route with a more specific prefix would still take precedence.
• B - System routes don't universally win; a UDR with a longer prefix overrides them.
• D - Route age is irrelevant to Azure's routing decision; there is no "newest wins" logic.

Memory tip: Think of it like a street address - "123 Main St, Austin, TX" is more specific than just "Austin, TX." Azure always delivers traffic using the most precise address (longest prefix) it has, just like a mail carrier would.

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