A router receives two routes from its neighbors: a route from OSPF for 10.0.0.0/24, and a route from BGP for 10.0.0.0/8. Both routes have reachable next hops. Which of the following is TRUE?

Question

Options

• AOnly the BGP route is in the route table.
• BBoth routes are in the route table.
• CNone of the routes is in the route table.
• DOnly the OSPF route is in the route table.

• A
  6% (3)
• B
  77% (37)
• C
  4% (2)
• D
  13% (6)

Explanation

Both routes are installed because they have different prefix lengths - /24 and /8 are distinct destinations, not competing routes to the same destination. Administrative distance (AD) only acts as a tiebreaker when two protocols advertise the exact same prefix; since these prefixes differ, both entries coexist in the routing table simultaneously.

Why distractors are wrong:

• A (Only BGP /8): Incorrect - the OSPF /24 is a different, more-specific prefix and is independently valid.
• C (None): Incorrect - both routes have reachable next hops, so there is no reason to discard either.
• D (Only OSPF /24): Incorrect - BGP's /8 covers a broader range not addressed by the /24, so it's also kept.

Memory tip: Think "same prefix = AD fight, different prefix = both win." When forwarding a packet, the router will then use longest prefix match to pick between them - a packet to 10.0.0.1 hits the OSPF /24, while a packet to 10.1.0.1 hits the BGP /8.

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