A network administrator wants to add a line to an access list that will block only Telnet access by the hosts on subnet 192.168.1.128/28 to the server at 192.168.1.5. What command should be issued to accomplish this task?（）

单项选择题Which protocol is an open standard protocol framework that is commonly used in VPNs,to provid secure end-to-end communication?（）

A. L2TP
B. IPsec
C. PPTP
D. RSA

单项选择题What is one benefit of PVST+?（）

A. PVST+reduces the CPU cycles for all the switches in the network
B. PVST+automatically selects the root bridge location,to provide optimized bandwidth usage.
C. PVST+allow the root switch location to be optimized per vlan.
D. PVST+supports Layer 3 load balancing without loops.

单项选择题Which item represents the standard IP ACL?（）

A. access-list 50 deny 192.168.1.1 0.0.0.255
B. access-list 110 permit ip any any
C. access-list 2500 deny tcp any host 192.168.1.1 eq 22
D. access-list 101 deny tcp any host 192.168.1.1

单项选择题Which statement about access lists that are applied to an interface is true?（）

A. you can apply multiple access lists with the same protocol or in different direction.
B. you can config one access list,per direction,per layer 3 protocol
C. you can place as many access lists as you want on any interface
D. you can apply only one access list on any interface

单项选择题Which command enables RSTP on a switch?（）

A. spanning-tree mode rapid-pvst
B. spanning-tree uplinkfast
C. spanning-tree backbonefast
D. spanning-tree mode mst