多选题Which two statements are true about voice VLANs？（）AVoice VLANs are only used when connecting an IP phone and a host to distinct switch portsBAccess ports that are configured with voice VLANs will always trust the CoS that is received from IP phonesCAcc

第1题：

第2题：

You have configured voice VLANs on Catalyst switch R1.  Which two statements are true about the  operation of voice VLANs on this device？ （）

• A、 When the voice VLAN feature is enabled， all untagged traffic is sent according to the default  CoS priority of the port.
• B、 Enabling voice VLANs enables the switch to create multiple queues for traffic that is entering a  port.
• C、 When voice VLANs are configured on a trunk link， UplinkFast must also be enabled.
• D、 Voice VLANs are configured to enable the switch to forward frames marked with the proper  CoS values over separate physical links.
• E、 Enabling voice VLANs enables the switch to forward frames with a specific 802.1P marking.

第3题：

第4题：

Which statement about vlan operation on cisco catalyst switches is true?（）

• A、when a packet is received from an 802.1Q trunk,the vlan id can be determined from the source MAC address table.
• B、unkown unicast frames are retransmitted only to the ports that belong to the same vlan
• C、ports between switches should be configured in access mode so that vlans can span across the ports
• D、broadcast and multicast frames are retransmitted to ports that are configured on different vlan.

第5题：

A switch has been configured with two vlans and is connected to a router with a trunk for inter-vlan routing.OSPF has been configured on the router，as the routing protocol for the network.Which statement about thisnetwork is true？（）

• A、For the two vlans to communicate，a network statement for the trunk interface needs to be added to the  OSPF configuration.
• B、For the two vlans to communicate， a network statement for each subinterface needs to be  added  to the OSPF configuration.
• C、Direct inter-vlan communication does not require OSPF
• D、OSPF cannot be used if router-on-a-stick is configured on the router

第6题：

Which two statements about voice VLANs are correct？（）

• A、Voice VLANs eliminate the need for QoS configuration
• B、Voice VLANs are used on trunk links to eliminate the need for QoS CoS markings
• C、Voice VLANs are mainly used to reduce the number of access switch ports that are used in the network
• D、Voice VLANs can be configured to forward existing CoS priorities or override them
• E、Voice VLANs are mainly used between access layer switches and distribution layer switches
• F、Voice VLANs can be configured on Layer 2 ports only

第7题：

Which two statements are true about voice VLANs？（）

• A、Voice VLANs are only used when connecting an IP phone and a host to distinct switch ports
• B、Access ports that are configured with voice VLANs will always trust the CoS that is received from IP phones
• C、Access ports that are configured with voice VLANs may or may not override the CoS value that is received from an IP phone
• D、Voice VLANs are configured using the switchport voice vlan vlan-ID interface configuration command
• E、Voice VLANs provide a trunking interface between an IP phone and an access port on a switch to allow traffic from multiple devices that are connected to the port
• F、Enabling Voice VLAN on a switch port will automatically configure the port to trust the incoming CoS markings

第8题：

第9题：

You need to configure a new Company Catalyst 3560 switch for a VOIP-enabled office.  Which  three statements are true about the voice VLAN feature on this switch？（）

• A、The default CoS value for incoming traffic is set up to 0.
• B、The CoS value is trusted for 802.1p or 802.1q tagged traffic.
• C、PortFast is automatically disabled when a voice VLAN is configured.
• D、The voice VLAN feature is disabled by default.
• E、The IP phone accepts the priority of all tagged and untagged traffic and sets the CoS value to 4.
• F、When the voice VLAN feature is enabled， all untagged traffic is sent according to the default  CoS priority of the port

第10题：

Which two statements are true about the configuration of voice VLANs？（）

• A、Static secure MAC addresses can be configured in conjunction with voice VLANs.
• B、PortFast is automatically enabled when voice VLANs are configured.
• C、PortFast must be manually configured when voice VLANs are configured.
• D、Voice VLANs are typically configured on uplink ports.
• E、Voice VLANs are typically configured on access ports.