A.Only UplinkFast and BackboneFast are specified in 802.1w； PortFast must be manually configured.
B.Only PortFast is specified in 802.1w； UplinkFast and BackboneFast must be manually configured.
C.None of the proprietary Cisco enhancements are specified in 802.1w.
D.PortFast， UplinkFast， and BackboneFast are specified in 802.1w.

A.Speed mismatch
B.Incorrect encapsulation
C.MTU set too low
D.Duplex mismatch

A.EBGP multihop will need to be configured for this to work.
B.This should work with normal BGP peering， with no additional configuration on the BGP speakers or the firewall.
C.The BGP protocol port must be opened on the firewall
D.There is no way to make BGP work across a firewall.

A.The stack bit will only be used when LDP is the label distribution protocol
B.The label is the last entry in the label stack.
C.The stack bit is for Cisco implementations exclusively and will only be used when TDP is the label distribution protocol.
D.The stack bit is reserved for future use.

A.Reverse Path Forwarding
B.Hardware-based forwarding
C.UDP forwarding
D.Layer 2 Forwarding

A.The firewall does not support Cisco Discovery Protocol. You should set the switchport trunk mode ON
B.The firewall does not support Cisco Discovery Protocol. You should set the switchport trunk mode to OFF
C.The firewall does not support Cisco Discovery Protocol. You should set the switchport trunk mode asauto.
D.The firewall does not support DTP. You should set the switchport trunk mode to ON

A.0.0.0.1
B.0.255.0.1
C.2001：DB8：：1
D.2001：DB8：ABCD：FEEF：：1

A.excessive collisions
B.FCS errors
C.runts
D.late collisions

A.BPDUs that enter a blocking port are discarded.
B.BPDUs that enter a blocking port are processed.
C.Loopguard puts an interface into a loop-inconsistent state when BPDUs stop being received on a blocking port.
D.BPDUs are only processed on forwarding ports.

A.The CBWFQ scheduler provides a guaranteed minimum amount of bandwidth to each class.
B.CBWFQ services each class queue using a strict priority scheduler.
C.The class-default queue only supports WFQ.
D.Inside a class queue， processing is always FIFO， except for the class-default queue.

A.It is a function used by routing protocols to install routes into routing table
B.It is a function that prevents the advertising of routes over an interface that the router is usingto reach a route
C.Its function is to help avoid routing loops.
D.It is a redistribution technique used by routing protocols