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VLAN管理策略服务器 英文为 VLAN Management Policy Server 简称VMPS。

VLAN Management Policy Server是基于源MAC地址动态的、在交换机端口上划分VLAN的方法。属于Client/Server架构。
VMPS包括一个映射MAC地址到VLAN分配的数据库。当一个帧到达动态端口时，交换机根据帧的源地址查询VMPS，获取相应的VLAN分配。
动态VLAN使用智能管理软件,可以基于MAC地址,协议,甚至应用程序来动态创建VLAN。Cisco 设备管理员可以使用VMPS的服务来建立个MAC地址数据库,来根据这个动态创建VLAN,VMPS数据库把MAC地址映射VLAN上。

VMPS工作原理:
当启动了VMPS以后，交换机首先会从一个预先指定好的TFTP服务器上下载MAC地址-VLAN的映射数据库，然后打开一个UDP进程来监听从客户端发来的请求，并进行处理。
当VMPS接到从客户端发来的一个合法请求后，首先查看数据库中是否有该MAC地址-VLAN的映射记录。如果有，则把对应的VLAN号发给客户端交换机；如果没有，且VMPS处于非安全模式下，则客户端只是简单地拒绝该主机的访问；同样是没有该MAC地址的映射记录，但VMPS处于安全模式下，则客户端交换机上连接该MAC的断口被关闭，要重新开启此端口，只有进行手工操作。
用户可以配置一个缺省的VLAN，如果数据库中没有该MAC的记录，则它会被分配到这个VLAN上。用户也可以使用NONE关键字来明确地指定一个MAC不能属于某个VLAN。
VMPS还提供了一些策略，以使VMPS配置起来更加灵活。这些策略包括端口组（Port-group）和VLAN组（VLAN-group）。

A VLAN Management Policy Server or “VMPS” is a network switch that contains a mapping of device information to VLAN.

The primary goal of VMPS is VLAN assignment for general network management purposes, but can also be used for providing security through segregating clients with an unknown MAC address, or through further extension of the protocol to provide login for Cisco ACS. This last functionality is now deprecated by Cisco, in favour of 802.1x, and as the VMPS technology is Cisco only, the VLAN assignment can now be carried out in the 802.1x framework.

Client switches query the VMPS server using the VLAN Query Protocol, or VQP. Only Cisco produces hardware with VMPS client functionality, and is currently fully supported across their IOS switching lines. Cisco officially only supports the use of Catalyst 4000, 5000 and 6500 switch platforms (with appropriate firmware) as VMPS servers, but these have limited functionality, and only support a static text file transferred into them with tftp.

Which two statements about the transmission of signals over a cable network are true? (choose two)
A. Downstream signals travel from the cable operator to the subscriber and use frequencies in the range
of 5 to 42 MHz
B. Downstream signals travel from the cable operator to the subscriber and use frequencies in the range
of 50 to 860 MHz
C. Downstream and upstream signals operate in the same frequency ranges
D. Upstream signals travel from the subscriber to the cable operator and use frequencies in the range of 5
to 42 MHz
E. Upstream signals travel from the subscriber to the cable operator and use frequencies in
the range of
50 to 860 MHz
Answer: BD

QUESTION 11
Refer to the exhibit. What information can be derived from this show ip cef command output?
Exhibit:
A. This router will use a label of “21″ to reach the destination network of 150.1.12.16
B. This router will use a PHP label to reach the destination network of 150.1.12.16
C. This router will advertise a label of “19″ for the destination network of 150.1.12.16
D. This router will advertise a label of “21″ for the destination network of 150.1.12.16
Answer: D