简答题 什么环境下需要用组播？

单项选择题Refer to the exhibit. You are setting up a 2-gigabit EtherChannel. Following IEEE standards, the exhibit shows your configuration in a local switch1. However, EtherChannel is not coming up. Which one of these statements could be a possible reason?（）

A.EtherChannel is only available in Cisco equipment.
B.The customer side is supposed to be running PAgP， which is a Cisco standard.
C.PAgP is not an IEEE standard. VRRP should be used.
D.The configuration on switch1 needs to be modified to use LACP.

问答题BGP选路的最优先参数是什么？

多项选择题WhichtwoprotocolscanhavetheirheaderscompressedthroughMQC？（）

A.RTP
B.RTSP
C.HTTP
D.TCP
E.UDP

单项选择题Whatisthedefaultmaximumreservablebandwidth（percentage）byanysingleflowonaninterfaceafterenablingRSVP？（）

A.75 percent
B.60 percent
C.56 percent
D.50 percent
E.25 percent

问答题网络安全涉及到OSI哪几层？