Refer to the exhibit. A network operator is configuring BGP PIC on CE1 on already established neighborships with PE1 and PE2 inside the fully converged MPLS network. Which element needs to be implemen

Question

Exhibit

Options

• ABidirectional Forwarding Detection must be applied to the upstream facing BGP interfaces
• BThe operator must ensure that all prefixes have the same next-hop from PE1 and PE2 for BGP PIC
• CA reserved BGP community of 1:10 must be used to denote the PIC feature set to the routing
• DBGP import export policies must be applied on all devices for the routes needing BGP for PIC

• A
  79% (45)
• B
  12% (7)
• C
  4% (2)
• D
  5% (3)

Explanation

BGP PIC (Prefix Independent Convergence) pre-installs backup paths in the FIB so that failover is nearly instantaneous when a primary path fails. However, PIC is only effective if the failure is detected quickly. BFD (Bidirectional Forwarding Detection) provides sub-second link failure detection on the upstream-facing BGP interfaces. Without BFD, failure detection relies on BGP keepalive timers (default 90 seconds hold-time), which is far too slow for PIC to be meaningful. BGP PIC on CE1 therefore requires BFD on the interfaces facing PE1 and PE2 to trigger rapid path switchover when a PE becomes unreachable.

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