Enable bpduguard globally.
Enable rootguard.
Enable loopguard.
Enable spanning tree.
Enable UDLD
第1题：
A. Show interface lmi
B. Show frame-relay lmi
C. Show interface frame-relay
D. Debug frame-relay interface.
第2题：
You are troubleshooting a problem with a cisco 7920 wireless ip phone that is causing the phone to drop calls. the problem appears to be a roaming bandwidth issuE. in order to verify what kind of issue it is， you decide to increase the bandwidth reserved for roaming on the wlan controller to the maximum. What level do you set the bandwidth to？（）
第3题：
While troubleshooting an issue in the Ezonexam LAN you notice that a network interface port has collision detection and carrier sensing enabled on a shared twisted pair network. From this statement, what is known about the network interface port?
A. This is an Ethernet port operating at half duplex
B. This is an Ethernet port operating at full duplex
C. This is a port on a network interface card in a PC
D. This is 10 MB/s switch port
E. This is a 100 MB/s switch port
F. None of the above
第4题：
When you are troubleshooting an ACL issue on a router,which command can help you to verify which interfaces are affected by the ACL?（）
第5题：
While you are troubleshooting network performance issues， you notice that a switch is periodically flooding all unicast traffic. Further investigation reveals that periodically the switch is also having spikes in CPU utilization， causing the MAC address table to be flushed and relearned. What is the most likely cause of this issue？（）
第6题：
A.show ip access-list
B.show access-list
C.list ip interface
D.show interface
E.show ip interface
第7题：
You delete a trace options file and later notice that no new entries are being written to this file. What would allow the entries to be written to the file again?（）
第8题：
While troubleshooting a network connectivity issue, you suspect that a router may be missing a route, or may be receiving bad routing information to a destination. What command should you issue to view the route that the router will use to reach a given destination?（）
A. ping
B. trace
C. show ip route
D. show interface
E. show cdp neighbors
第9题：
You’re a network administer and you issue the command （show port 3/1） on an Ethernet port. Toyour surprise you notice a non-zero entry in the ’Giants’ column. What could be the cause of this？（）
第10题：
While troubleshooting a network connectivity issue, you suspect that a router may be missing a route, or may be receiving bad routing information to a destination. What command should you issue to view the route that the router will use to reach a given destination?（）