多项选择题 Which two of the following actions must an OSPF NSF-capable router execute after a supervisor engine switchover?（） (Choose two.)

单项选择题 What is the purpose of IP Event Dampening?（）

多项选择题 CIS .com recently acquired a smaller competitor. The acquired company is not currently using Cisco routers, so you have connected the two WANs via an authenticated PPP link. After configuration both routers, issuing the show interface s0/0 command on the Cisco Router shows the interface to be in the up/down state. Which two of these are possible causes? （）