1、Which two tasks does the Dynamic Host Configuration Protocol perform? (Choose two.)

　　DHCP服务器 在网络中作用。

　　A. Set the IP gateway to be used by the network. 通过网关设置网关， 错。

　　B. Perform host discovery used DHCPDISCOVER message.

　　C. Configure IP address parameters from DHCP server to a host.

　　通过DHCP 服务器给主机分配IP地址

　　D. Provide an easy management of layer 3 devices.

　　E. Monitor IP performance using the DHCP server.

　　F. Assign and renew IP address from the default pool. 从默认地址池中分配和重新获取IP地址

　　Answer: CF

　　2、When a DHCP server is configured, which two IP addresses should never be assignable to hosts? (Choose two.) 当一个DHCP配置好的时候，哪两个地址将永远不会分配给主机?

　　A. network or subnetwork IP address

　　B. broadcast address on the network

　　C. IP address leased to the LAN

　　D. IP address used by the interfaces

　　E. manually assigned address to the clients

　　F. designated IP address to the DHCP server

　　Answer: AB

　　网段地址和广播地址。其他地址都可能会被分配。 所以我们在做DHCP的时侯，会保留一部分地址不放在地址池中

　　3、 Which statement describes the process of dynamically assigning IP addresses by the DHCP server? 那一个选项描述了DHCP动态分配地址的过程?

　　A. Addresses are allocated after a negotiation between the server and the host to determine the length of the agreement. 在DHCP租约期限一半时，DHCP客户端会提交租约续订请求到DHCP服务器。如果DHCP服 务器在联机状态，那么通 常DHCP服务器会接受续订，然后租约周期重新开始 。如果DHCP服务器不可用那

　　B. Addresses are permanently assigned so that the hosts uses the same address at all times.

　　C. Addresses are assigned for a fixed period of time, at the end of the period, a new request for an address must be made. DHCP客户端会在剩余一半的租约周期过去后尝试再次续订DHCP租约。如果在 租约时间的87.5%过去后DHCP服务器仍然不可用， DHCP客户端会尝试寻找一个新的DHCP服务器，并可能获 取一个不同的IP地址

　　D. Addresses are leased to hosts, which periodically contact the DHCP server to renew the lease. 地址被租用给主机，需要定期的和dhcp服务器联系以获得新的租约。

　　Answer: D 根据以上分析可得出答案D 为正确的