单项选择题
A.ip sla 1 icmp-echo 1.1.1.1 tos 160 B.ip sla 1 icmp-echo 1.1.1.1 tos 20 C.ip sla 1 icmp-echo 1.1.1.1 precedence 5 D.ip sla 1 icmp-echo 1.1.1.1 dscp 20
A.The phones are not sending traffic with the correct DSCP value. B.The Cisco CallManager is not marking the traffic correctly. C.This is most likely a bug on the CE routers. D.Your LAN QoS is incorrectly configured.
A.routing issue B.denial-of-service attack C.MAC flooding D.spanning-tree recalculation E.Layer 2 loop F.ARP spoofing attack