简答题

根据R2上面的配置，请判断pc能否反问internet。  
R2：ip route 0.0.0.0 0.0.0.0 10.1.1.2     
No ip classess

A.Guaranteed PHB
B.Class-Selector PHB
C.Reserved Forwarding PHB
D.Discard Eligible PHB
E.Priority PHB

A.with traffic shaping，a router stores excess traffic in packet buffers until bandwidth is available again
B.with policing you can tune the buffer usage for traffic exceeding the specified CIR
C.with shaping you can tune the buffer usage for traffic exceeding the specified CIR
D.shaping should only be applied for ingress traffic，policing only for egress
E.policing uses a token bucket algorithm，shaping uses an SPD algorithm