A.All ports will be in forwarding mode.
B.All ports in VLAN 10 will be in forwarding mode.
C.All ports in VLAN 10 will be in forwarding mode and all ports in VLAN 20 will be in blocking mode.
D.All ports in VLAN 10 will be in forwarding mode and all ports in VLAN 20 will be in standby mode.

A.BPDU port-guard can be enabled globally， whereas BPDU filtering must be enabled on a per-interface basis.
B.When globally enabled， BPDU port-guard and BPDU filtering apply only to PortFast enabled ports.
C.When globally enabled， BPDU port-guard and BPDU filtering apply only to trunking-enabled ports.
D.When a BPDU is received on a BPDU port-guard enabled port， the interface goes into the err-disabled state.
E.When a BPDU is received on a BPDU filtering enabled port， the interface goes into the err-disabled state.
F.When a BPDU is received on a BPDU filtering enabled port， the interface goes into the STP blocking state.

A.The root port on switch SW_A will automatically transition to full-duplex mode.
B.The root port on switch SW_B will fallback to full-duplex mode.
C.The interfaces between switches SW_A and SW_B will transition to a blocking state.
D.Interface Fa 0/6 on switch SW_B will transition to a forwarding state and create a bridging loop.

A.mon Spanning Tree maintains a separate spanning-tree instance for each VLAN configured in the network.
B.The Spanning Tree Protocol （STP） is an evolution of the IEEE 802.1w standard.
C.Per-VLAN Spanning Tree （PVST） supports 802.1Q trunking.
D.Per-VLAN Spanning Tree Plus（PVST+） is an enhancement to 802.1Q specification and is supported only on Cisco devices.
E.Rapid Spanning Tree Protocol （RSTP） includes features equivalent to Cisco PortFast， UplinkFast， and BackboneFast for faster network reconvergence.
F.Multiple Spanning Tree （MST） assumes one spanning-tree instance for the entire Layer 2 network， regardless of the multiple number of VLANs

A.to display rewritten IP unicast packets
B.to display ARP resolution packets
C.to display ARP throttling
D.to display TCAM matches
E.to display CEF-based MLS lookups
F.to display entries in the Forwarding Information Base （FIB）

A.The port on switch CAT1 is forwarding and sending BPDUs correctly.
B.The port on switch CAT1 is blocking and sending BPDUs correctly.
C.The port on switch CAT2 is forwarding and receiving BPDUs correctly.
D.The port on switch CAT2 is blocking and sending BPDUs correctly.
E.The port on switch CAT3 is forwarding and receiving BPDUs correctly.
F.The port on switch CAT3 is forwarding， sending， and receiving BPDUs correctly.

A.enables LACP unconditionally
B.enables PAgP only if a PAgP device is detected
C.enables PAgP unconditionally
D.enables Etherchannel only
E.enables LACP only if a LACP device is detected

A.The switch port attached to LinkB will not transistion to up.
B.One of the two switch ports attached to the hub will go into blocking mode when a BPDU is received.
C.Both switch ports attached to the hub will transition to the blocking state.
D.A heavy traffic load could cause BPDU transmissions to be blocked and leave a switching loop. 
E.The switch port attached to LinkA will immediately transition to the blocking state.

A.All ports will temporarily transition to the learning state for a period equal to the max age timer plus the forward delay interval.
B.All ports will transition temporarily to the learning state for a period equal to the forward delay interval.
C.The default aging time for MAC address entries will be reduced for a period of the max age timer plus the forward delay interval.
D.The default hello time for configuration BDPUs will be reduced for the period of the max age timer.

A.The port immediately transitions to the Forwarding state.
B.The switch generates a Topology Change Notification （TCN） BPDU.
C.The port immediately transitions to the err-disable state.
D.The port becomes a normal STP switch port.