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

A.Security increases because only the network administrator may change the routing tables.
B.Configuration complexity decreases as network size increases.
C.Routing updates are automatically sent to neighbors.
D.Route summarization iscompued automatically by the router.
E.Routing traffic load is reduced when used in stub network links
F.An efficient algorithm is used to build routing tables,using automatic updates.
G. Routing tables adapt automatically to topology changes.

A.DES
B.3DES
C.AES
D.SEAL

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

A.生成
B.驗證
C.存儲
D.撤銷和銷毀

A.The address is a broadcast address
B.The Ehernet interface is faulty
C.VLSM-capable routing protocols must be enable first on the router.
D.This address is a network address.

A.2031：0：130F：：9C0：876A：130B
B.2001：0DB8：0000：130F：0000：0000：08G
C.140BC.2001：0DB8：0：130H：：87C：140B
D.2031：：130F：：9C0：876A：130B

A.MD5
B.RSA
C.HMAC
D.SHA-1

A.you can apply multiple access lists with the same protocol or in different…
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 ony one access list on any interface

A.to confine network instability to single areas of the network
B.to reduce the complexity of router configuration
C.to speed up convergence
D.to lower costs by replacing routers with distribution layer switches
E.to decrease latency by increasing bandwidth
F.to reduce routing overhead