Which two QoS classification and marking statements are true

第1题：

Which two QoS classification and marking statements are true？ （）

• A、 In a Frame Relay network， delay sensitive traffic is tagged with the discard eligible （DE） bit.
• B、 In an MPLS network， the three most significant bits of the DSCP or the IP precedence of the IP packet are copied into the MPLS EXP field.
• C、 In an MPLS network， the MPLS EXP bits are used to identify up to 16 CoS values.
• D、 The differentiated services code point （DSCP） field consists of the first three bits of the IP precedence field in the header of an IP packet.
• E、 The 802.1Q standard uses a three bit field referred to as the user priority bits （PRI） to mark packets as belonging to a specific CoS.

第2题：

Which two statements are true about Unicast Reverse Path Forwarding Loose Mode？（）

• A、It is used in multihome network scenarios.
• B、It can be used with BGP to mitigate DoS and DDoS.
• C、It does not need to have CEF enabled.
• D、It is enabled via the interface level command ip verify unicast reverse-path.
• E、It cannot be used with "classification" access lists.

第3题：

Which two Cisco AutoQoS configuration statements are true？ （）

• A、the auto discovery qos command is supported on serial interfaces， subinterfaces， and virtual interfaces
• B、CEF must be enabled before configuring the auto discovery qos command
• C、the auto discovery qos privilege EXEC command must be configured on a router for several days to collect a sampling of data traffic
• D、the auto qos trust command relies on NBAR to provide VoIP classification
• E、the auto qos voip command configures the voip classification on routers and switches

第4题：

Which three statements are true about policing？ （）

• A、Out-of-profile packets are queued.
• B、It causes TCP retransmits.
• C、Marking and remarking are not supported.
• D、It does not respond to BECN and foresight messages.
• E、It uses a single- and two-bucket mechanism for metering.

第5题：

Which two statements about the best effort model for QoS are true？（）

• A、delay sensitive packets are given preferential treatment
• B、the default policy identifies a delay sensitive class and default class
• C、the default policy identifies a delay sensitive class， best effort class， and default class
• D、the model is highly scalable
• E、the model is still predominant on the internet F the model provides guaranteed service

第6题：

Which two QoS classification and marking statements are true？（）

• A、 In a Frame Relay network， delay sensitive traffic is tagged with the discard eligible （DE） bit.
• B、 In an MPLS network， the three most significant bits of the DSCP or the IP precedence of the IP packet are copied into the MPLS EXP field
• C、 In an MPLS network， the MPLS EXP bits are used to identify up to 16 CoS values.
• D、 The differentiated services code point （DSCP） field consists of the first three bits of the IP precedence field in the header of an IP packet.
• E、 The 802.10 standard uses a three bitfield referred to as the user priority bits （PRI） to mark packets as belonging to a specific CoS.

第7题：

Which two statements are true about L2TP tunnels?（） (Choose two.)

• A、Traffic is clear text
• B、Traffic is encrypted 
• C、They are initiated by the LNS
• D、They are initiated by the LAC

第8题：

Which two statements or sets of statements are true about the application of the qos pre-classify command？（）

• A、 If the classification policy is based upon the ToS byte， the qos pre-classify command is required because the ToS byte only appears in the inner IP header.
• B、 The ToS byte is copied to the outer header by default. Therefore， the qos pre-classify command is not necessary.
• C、 With GRE encapsulation， the qos pre-classify command is applied on the tunnel interface. This practice allows for different OoS configurations on each tunnel.
• D、 With GRE encapsulation， the qos pre-classify command is applied on the physical interface. This practice allows for different OoS configurations on each interface.
• E、 With IPsec encapsulation， the qos pre-classify command is applied on the physical interface. This practice allows for different OoS configurations on each interface.

第9题：

Which two statements are true about traffic shaping？（）

• A、Out-of-profile packets are queued.
• B、It causes TCP retransmits.
• C、Marking/remarking is not supported.
• D、It does not respond to BECN and ForeSight Messages.
• E、It uses a single/two-bucket mechanism for metering.

第10题：

Which two statements about the QoS policy generation phase of the Cisco SDM QoS wizard are true？（）

• A、the SDM QoS wizard will create two real-time traffic classes to handle VoIP， voice signaling， and video packets
• B、the SDM QoS wizard will create three real-time traffic classes to handle VoIP， voice signaling， video， and video packets
• C、the SDM QoS wizard will create four real-time traffic classes to handle VoIP， voice signaling， video， and video streaming packets
• D、the SDM QoS wizard will create two business-critical traffic classes to handle transactional and  network management packets
• E、the SDM QoS wizard will create three business-critical traffic classes to handle transactional， network management， and routing packets
• F、the SDM QoS wizard will create four business-critical traffic classes to handle transactional， network management， routing， and best-effort packets