Which three statements about the DHCP snooping feature on Cisco Nexus switches are true？ （）

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.

A . Multicast addresses 224.0.0.0 through 224.0.0.255 are always forwarded because they are transmitted  with Time to Live （TTL） greater than 1. B . Multicast addresses 224.0.0.5 and 224.0.0.6 are source multicast addresses for OSPF routers. C . Multicast addresses 224.0.0.13 and 224.0.0.22 are reserved link-local addresses used by PIMv2 and  IGMPv3. D . Because they would map to overlapping IP multicast MAC addresses， multicast addresses 224.0.1.1  and 238.1.1.1 could not be used together. E . Multicast address 224.0.1.1 has been reserved for the Network Time Protocol （NTP） by the IANA F . The administratively scoped multicast addresses 239.0.0.0 through 239.255.255.255 are similar in  purpose to RFC 1918 private unicast addresses.

A . Utilizing Syslog improves network performance. B . The Syslog server automatically notifies the network administrator of network problems. C . A Syslog server provides the storage space necessary to store log files without using router disk space. D . There are more Syslog messages available within Cisco IOS than there are comparable SNMP trap messages. E . Enabling Syslog on a router automatically enables NTP for accurate time stamping。 F . A Syslog server helps in aggregation of logs and alerts.

A . RSTP significantly reduces topology reconverging time after a link failure. B . RSTP expends the STP port roles by adding the alternate and backup roles. C . RSTP port states are blocking，discarding，learing，or forwarding. D . RSTP also uses the STP proprsal-agreement sequence. E . RSTP use the same timer-baseed process as STP on point-to-point links. F . RSTP provides a faster transition to the forwarding state on point-to-point links than STP does.

A .  A user cannot set privileges on the persistent lightweight jobs B .  Persistent lightweight jobs generate a large amount of metadata C .  It is possible to create fully self-contained persistent lightweight jobs D .  The use of a template is mandatory to create persistent lightweight jobs E .  Persistent lightweight jobs are useful when users need to create a large number of jobs in a short time

A . Asinglerowsubquerycanretrieveonlyonecolumnandonerow. B . Asinglerowsubquerycanretrieveonlyonerowbutmanycolumns. C . Amultiplerowsubquerycanretrievemultiplerowsandmultiplecolumns. D . Amultiplerowsubquerycanbecomparedusingthe"；>；"；operator. E . AsinglerowsubquerycanusetheINoperator. F . Amultiplerowsubquerycanusethe"；="；operator.

A . Subqueries can contain GROUP BY and ORDER BY clauses  B . Main query and subquery can get data from different tables  C . Main query and subquery must get data from the same tables  D . Subqueries can contain ORDER BY but not the GROUP BY clause  E . Only one column or expression can be compared between the main query and subquery F .  Multiple columns or expressions can be compared between the main query and subquery

A . RSTP significantly reduces topology reconverging time after a link failure. B . RSTP expends the STP port roles by adding the alternate and backup roles. C . RSTP port satates are blocking,discarding,learing,or forwarding. D . RSTP also uses the STP proprsal-agreement sequence. E . RSTP use the same timer-baseed process as STP on point-to-point links. F . RSTP provides a faster transition to the forwarding state on point-to-point links than STP does.

A . A final method in class X can be abstract if and only if X is abstract. B . A protected method in class X can be overridden by any subclass of X. C . A private static method can be called only within other static methods in class X. D . A non-static public final method in class X can be overridden in any subclass of X. E . A public static method in class X can be called by a subclass of X without explicitly referencing the class X. F . A method with the same signature as a private final method in class X can be implemented in a subclass of X. G . A protected method in class X can be overridden by a subclass of X only if the subclass is in the same package as X.

A . includes three design levels B . incorporates products and technologies into enterprise, service provider, and commercial systems C . extends the value of designs through a sustained development plan D . does not factor customer input design process E . facilitates faster and more reliable customer deployments F . incorporates a narrow range of technologies and product

A . A single row subquery can retrieve only one column and one row. B . A single row subquery can retrieve only one row but many columns. C . A multiple row subquery can retrieve multiple rows and multiple columns. D . A multiple row subquery can be compared by using the ">" operator. E . A single row subquery can use the IN operator. F . A multiple row subquery can use the "=" operator.

A . A user cannot set privileges on the persistent lightweight jobs B . Persistent lightweight jobs generate a large amount of metadata C . It is possible to create fully self-contained persistent lightweight jobs D . The use of a template is mandatory to create persistent lightweight jobs E . Persistent lightweight jobs are useful when users need to create a large number of jobs in a short time

A .  The default constructor initializes method variables. B .  The default constructor has the same access as its class. C .  The default constructor invoked the no-arg constructor of the superclass. D .  If a class lacks a no-arg constructor， the compiler always creates a default constructor.  E .  The compiler creates a default constructor only when there are no other constructors for the class.

A . EIGRP converges fast RIP because of DUAL and backup routes that are stored in the topology table. B . EIGRP uses a hello protocol to establish neighbor relationships C . EIGRP uses split horizon and reverse poisoning to avoid routing loops. D . EIGRP uses periodic updates to exchange routing information E . EIGRP allows routers of different manufacturers to interoperate F . EIGRP supports VLSM and authentication for routing updates. G . EIGRP use a broadcast address to send routing information.

A . DAI intercept all ARP packets on untrusted ports B . DAI determines the validity of an ARP packet based on the valid MAC address-to-IP address bindings stored in the DHCP Snooping database. C . DAI is used to prevent against a DHCP Snooping attack. D . DAI forwards all ARP packets received on a trusted interface without any checks. E . DAI forwards all ARP packets on untrusted ports. F . DAI determines the validity of an ARP packet based on the valid MAC address-to-IP address bindings stored in the CAM table.

A . It has the same maximum hop count as version 1. B . It uses broadcasts for its routing updates. C . It is a classless routing protocol. D . It has a lower default administrative distance than RIP version 1. E . It supports authentication. F . It does not send the subnet mask in updates.

A . It is a Cisco proprietary protocol. B . It runs on TCP port 59. . C . Authentication and authorization are done at different stages. D . TACACS+ encrypts the entire body of the packet， but leaves a standard TACACS+ header. E . It is an industry standard protocol. F . TACACS+ encrypts both the entire body of the packet and the TACACS+ header.

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.

A . NetFlow records unidirectional IP traffic flow. B . NetFlow records MPLS frame flow. C . NetFlow expert is only over TCP. D . NetFlow records is only over UDP. E . NetFlow records subinterface information of traffic flow.

A .  Only one window can be open at any given time B .  Consumer groups are associated with windows C .  Windows work with job classes to control resource allocation D .  The database service name must be provided during windows creation E .  Windows can automatically start job or change resource allocation among jobs for various time periods.

A .  A lightweight AP receives control and configuration from a WLAN controller to which it is associated. B .  A WLAN client that is operating in half-duplex mode will delay all clients in that WLAN C .  A dhoc mode allows mobile clients to connect directly without an intermediate AP D .  Another term for infrastructure mode is independent service set （IBSS） E .  The Aironet 1230 access point is an example of an access point that operates solely as a lightweight  access point. F .  WLANs are designed to share the medium and can easily handle an increased demand of channel  contention.

A . Cisco Express Forwarding （CEF） must be enabled as a prerequisite to running MPLS on a Cisco router. B . Frame-mode MPLS inserts a 32-bit label between the Layer 3 and Layer 4 headers. C . MPLS is designed for use with frame-based Layer 2 encapsulation protocols such as Frame Relay， but is not supported by ATM because of ATM fixed-length cells. D . OSPF， EIGRP， IS-IS， RIP， and BGP can be used in the control plane. E . The control plane is responsible for forwarding packets. F . The two major components of MPLS include the control plane and the data plane.