单项选择题
Which of the following IOS features can prevent IP spoofing attacks？（）
A.PPP over Ethernet B.Cisco Express forwarding C.MPLS traffic Engineering D.IS-IS routing E.Unicast Reverse Path Forwarding（uRPF）
多项选择题 MPLSlabelheadersforpacketmediaconsistof（）.
单项选择题 InthecontextofMPLS，whatisthecorrectactiontobeperformedwhenanaggregatelabelisreceived？（）
单项选择题 GMPLSisbasedupon：（）
