A.Addresses are allocated after a negotiation between the server and the host to determine the length ofthe agreement.
B.Addresses are assigned for a fixed period of time.At the end of period，a newquest for an address mustbe made ，and another address is then assigned.
C.Addresses are leased to host.A host will usually keep the same address by periodicallycontacting theDHCP sever to renew the lease.
D.Addresses are permanently assigned so that the host uses the same address at all times.

A.spanning-tree backbonefast
B.spanning-tree uplinkfast
C.spanning-tree portfast
D.spanning-tree cost512

A.拒絕服務器攻擊
B.IP地址欺騙
C.DOS TCP SYN攻擊
D.DOS smurf攻擊

A.802.3ad
B.802.1w
C.802.1Q
D.802.1d

A.每個用戶的挑戰(zhàn)驗證機制
B.簡化路由器對ACL的處理
C.降低網(wǎng)絡黑客對網(wǎng)絡的攻擊機會
D.在不損害其他安全配置的前提下，可以動態(tài)的讓用戶穿越防火墻

A.data integrity
B.encryption
C.key exchange
D.authentication

A.ping
B.tracert
C.ipconfig
D.show ip route
E.winipcfg
F.show interfaces

A.show secure
B.show file systems
C.show flash
D.show version

A.nly passwords configured after the command has been entered will be encrypted.
B.Only the enable password will be encrypted.
C.Only the enable secret password will be encrypted
D.It will encrypt the secret password and remove the enable secret password from the configuration.
E.It will encrypt all current and future passwords.

A.SW1#show swithport port-security interface FastEthernet 0/12
B.SW1# show swithport port-secure interface FastEthernet 0/12
C.SW1# show port-secure interface FastEthernet 0/12
D.SW1#show running-config