单项选择题
A. CIS 1# show class-map forward Class map match-all forward ( id 3) Match ip dscp 18
B. CIS1#show access-map block Class map match-all block (id 4) Match ip dscp 43
C. CIS1# show class-map real-time Class map match-all block (id 5) Match ip dscp 16
D. CIS 1# show class-map pass Class map match-all real-time (id 2) Match ip dscp 40
多项选择题 You are an experienced network administrator in an international company. During your working hours, customers complain that they experience intermittent data loss and they intermittently fail to connect to crucial servers. As shown in the following topology, the 802.1Q trunk between DSW111 and ASW1 fails. Though DSW112 is in the service of HSRP group 11, the SVI for VLAN 11 is up on DSW111. So as to figure out the problem, which three commands should you issue on DSW111? （）(Choose three.)
单项选择题 You are troubleshooting an issue which is causing full-sized packets entering the MPLS cloud be dropped. You have discovered that one of the switches in the MPLS core is not a Cisco switch, but otherwise the MPLS MTU size is set to 1508 bytes on the routers. Based on this information, which of these may be the reason the packets are being dropped?（）
单项选择题 Assuming that an IP packet is sent from a source address in VLAN1 to a destination address in VLAN2 through a layer-3 switch, which part of the packet will be changed?（）