单项选择题
A.The hello dead timer expires. B.The restart duration timer expires. C.The restarting router sets the down bit. D.The restart helper sends out three CSNPs.
A.63 B.64 C.1023 D.1024 E.65535
A.Level 1 internal routes B.Level 1 external routes C.Level 2 internal routes D.Level 2 external routes