A network administrator is using a LAN analyzer to troubleshoot OSPF router exchange messages sent to ALLOSPF ROUTERS. To what MAC address are these messages sent？（）

单项选择题AccordingtoRFC3180，whatisthecorrectGLOPaddressforAS456？（）

A. 224.0.4.86
B. 224.4.86.0
C. 233.1.200.0
D. 239.2.213.0
E. 239.4.5.6

多项选择题WhataretwoimportantguidelinestofollowwhenimplementingVTP？（）

A. CDPmust be enabled on all switches in theVTP management domain.
B. All switches in the VTPdomain must run the same version of VTP.
C. When using secure mode VTP， only configure management domain passwords onVTP servers.
D. EnablingVTP pruning on a server willenable the feature for the entire management domain.
E. Use of theVTPmulti-domain feature should be restricted to migration and temporary implementation.

多项选择题Whataretwokeycharacteristicsof VTP？（）

A.VTP messages are sent out all switch-switch connections.
B.VTP L2 messages are communicated to neighbors using CDP.
C.VTP manages addition， deletion， and renaming of VLANs 1 to 4094.
D.VTP pruning restricts flooded traffic， increasing available bandwidth.
E.VTP V2 can only be used in a domain consisting of V2 capable switches.
F.VTP V2 performs consistency checks on all sources of VLAN information.

单项选择题HowdoTCPSYNattackstakeadvantageofTCPtopreventnewconnectionsfrombeingestablishedtoahostunderattack？（）

A.These attacks send multiple FIN segments forcing TCP connection release.
B.These attacks fill up a hosts’ listen queue by failing to ACK partially openedTCPconnections.
C.These attacks take advantage of the hosts transmit backoff algorithm by sending jam signals to the host.
D.These attacks increment the ISN of each segment by a random number causing constant TCP retransmissions.
E.These attacks send TCP RST segments in response toconnection SYN+ACK segments forcing SYN retransmissions.