An administrator configured the following command on FortiGate. config router ospf set restart-mode graceful-restart Which two statements correctly describe the result of the above command? (Choose…

Question

Options

• AIn an HA cluster, FortiGate devices will keep the OSPF routes in their routing table to avoid traffic
• BThe OSPF neighbor that receives the grace link-state advertisement (LSA) will enter into helper
• CAfter the default 40 seconds wait time, the OSPF neighbors will resume communication with the
• DFortiGate is configured with graceful restart, and will exit graceful mode, if the network topology

• A
  75% (18)
• C
  8% (2)
• D
  17% (4)

Explanation

Enabling OSPF graceful restart on FortiGate tells the device to maintain its OSPF forwarding table during a restart event (such as an HA failover), which keeps traffic flowing rather than dropping it - making A correct. When graceful restart begins, the restarting FortiGate floods a Grace LSA to its neighbors; those neighbors recognize the LSA and enter helper mode, where they continue treating the restarting device as fully adjacent and suppress any topology change notifications - making B correct.

C is wrong because the default grace period on FortiGate is 120 seconds, not 40 seconds; after that window expires without a successful restart, neighbors drop the adjacency - not simply "resume communication." D is wrong because while it's true that a topology change causes helper routers to exit helper mode, this describes a failure/exit condition rather than what the command actually accomplishes; it also conflates the helper's behavior with FortiGate's own graceful-restart role.

Memory tip: Think of graceful restart as a "hold your breath" deal - the restarting router holds its routes (A) while its neighbors hold their opinions via the Grace LSA (B). If either side detects something unexpected (topology change, timer expiry), the deal is off - but the default patience window is 120 seconds, not 40.

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