A.ATT（Attached）bit
B.IS-Type bits
C.P（Partition）bit
D.Down bit
E.PN（Pseudonode）biy
F.ABR（Area Border Rorter）bit

A.The total end-to-end delay
B.The variations of delay.
C.The delay caused by placing the bits on the wire.
D.The time it takes for the bits to transit the physical media.

A.A priority of 0 will prevent a router from becoming a DIS.
B.If the DIS becomes unavailable the backup DIS is promoted to DIS.
C.Adding a router with a higher priority than the current DIS will result in the new router becoming DIS.
D.Separate L1 and L2 election processes are held on a brodcast network.
E.L1 routers on a broadcast network only establish adjacencies with the DIS.
F.If there is a tie based on priority，the router whose attached interface has the lowest MAC address becomes the DIS.

A.Custom Queueing
B.CB-WRED
C.WRR Queueing
D.LLQ
E.CBWFQ

A.IP protocol 50
B.IP protocol 51
C.TCP port 50
D.TCP port 51
E.UDP port 50
F.UDP port 51

A.terminating PPP sessions at the service provider
B.PPP framing
C.PPP multiplexing
D.GRE tunneling
E.L2TP tunneling

A.multicast temporary node local
B.multicast temporary site local
C.unicast permanent link local
D.multicast permanent node link local
E.multicast permanent site local
F.unicast temporary link local

A.LSP
B.PSNP
C.ISH
D.CSNP
E.IIH

A.EIGRP supports VLSM， route summarization， and routing update authentication.
B.If the feasible successor has a higher advertised distance than the successor route， it becomes the primary route.
C.Passive routes are in the process of being calculated by DUAL.
D.EIGRP exchanges full routing table information with neighboring routers with every update.
E.A query process is used to discover a replacement for a failed route if a feasible successor is not identified from the current routing information.

A.VPLS uses LDP for signaling.
B.VPLS uses BGP for autodiscovery and signaling.
C.VPLS uses extended IS-IS for signaling
D.VPLS uses OSPF version 3 for auto discovery and signaling
E.VPLS uses spanning tree for signaling