While using a packet analyzer， you notice four additional bytes being added to the packets in the  Company network.  Which protocol inserts a four byte tag into the Ethernet frame and recalculates  CRC value？  （）A、 DTPB、 VTPC、 802.1QD、 ISLE、 None of the o

第1题：

第2题：

What are two things that an access point （AP） does when it receives an 802.11 frame from a Wi-Fi Multimedia （WMM） client？ （）

• A、EAP-FASTEAP-FAS Access Point Protocol （LWAPP） packet is used to generate an 802.1 p priority value in the packets， which are sent to an Ethernet switch by the controllers.
• B、The AP will police the 802.1 le priority value to ensure it does not exceed the maximum value allowed for the QoS policy that is assigned to that client.
• C、Once the LWAPP packet is received， the AP generates the IEEE 802.1 p priority value.
• D、The AP will map the 802.11e priority value to the DSCP value.
• E、The AP will map the DSCP value to the outer LWAPP frame.

第3题：

第4题：

ISL is being configured on a Company switch.  Which of the following choices are true regarding  the ISL protocol？ （）

• A、 It can be used between Cisco and non-Cisco switch devices.
• B、 It calculates a new CRC field on top of the existing CRC field.
• C、 It adds 4 bytes of protocol-specific information to the original Ethernet frame.
• D、 It adds 30 bytes of protocol-specific information to the original Ethernet frame.

第5题：

You are troubleshooting an issue which is causing full-sized packets entering the MPLS cloud be dropped. You have discovered that one of the switches in the MPLS core is not a Cisco switch, but otherwise the MPLS MTU size is set to 1508 bytes on the routers. Based on this information, which of these may be the reason the packets are being dropped?（）

• A、The switch on you MPLS core that was not produced by Cisco does not support oversized packets
• B、No switches support oversized packets
• C、By definition, the maximum MTU is 1500 bytes
• D、As MPLS VPN labeling increases the size of the packet by 8 bytes, the IP MTU should have been changed to 1508

第6题：

第7题：

You need to implement a high availability design in the Company routed network.  Which protocol  allows for the automatic selection and simultaneous use of multiple available gateways as well as  automatic failover between those gateways？（）

• A、 VRRP
• B、 GLBP
• C、 IRDP
• D、 HSRP
• E、 None of the other alternatives apply

第8题：

第9题：

Two Company switches are connected via a trunk link. In this network， the original frame is  encapsulated and an additional header is added before the frame is carried over a trunk link. At  the receiving end， the header is removed and the frame is forwarded to the assigned VLAN.  This  describes which technology？（）

• A、 DISL
• B、 ISL
• C、 DTP
• D、 IEEE 802.1Q
• E、 MPLS
• F、 None of the other alternatives apply

第10题：

The core Company switches are configured to use 802.1Q trunks.  Which three statements are  correct with regard to the IEEE 802.1Q standard？（）

• A、 The IEEE 802.1Q frame format adds a 4 byte field to a Ethernet frame
• B、 The packet is encapsulated with a 26 byte header and a 4 byte FCS
• C、 The protocol uses point-to-multipoint connectivity
• D、 The protocol uses point-to-point connectivity
• E、 The IEEE 802.1Q frame uses multicast destination of 0x01-00-0c-00-00
• F、 The IEEE 802.1Q frame retains the original MAC destination address