多项选择题
A.hello packets
B.SAP messages sent by other routers
C.LSAs from other routers
D.beacons received on point-to-point links
E.routing tables received from other link-state routers
F.TTL packets from designated routers
单项选择题 Which command can be a router to verify the layer 3 path to a host?（）
单项选择题 Which command reveals the last method used to power cycle a router?（）
多项选择题 Before installing a new, upgraded version of the IOS, what should be checked on the router, and which command should be used to gather this information? （）