A.Switch SW1 has been configured with the spanning-tree vlan 1 root primary global configuration command.
B.Switch SW1 has been configured with the spanning-tree vlan 1 root secondary global configuration command.
C.Switch SW1 has been configured with the spanning-tree vlan 1 priority 24577 global configuration command.
D.Switch SW1 has been configured with the spanning-tree vlan 1 hello-time 2 global configuration command.
E.The root bridge has been configured with the spanning-tree vlan 1 root secondary global configuration command.

A.All ports of the root switch SW_A will remain in forwarding mode throughout the reconvergence of the spanning tree domain.
B.Switch SW_A will change its spanning tree priority to become root for VLAN 2 only.
C.Switch SW_A will remain root for the default VLAN and will become root for VLAN 2.
D.No other switch in the network will be able to become root as long as switch SW_A is up and running.

A.The command will be rejected by the switch.
B.Interfaces FastEthernet0/13 and FastEthernet0/14 will no longer be bundled.
C.Dynamic Trunking Protocol will be turned off on interfaces FastEthernet0/13 and FastEthernet0/14.
D.Interfaces FastEthernet0/13 and FastEthernet0/14 will only allow traffic from the native VLAN.
E.Interfaces FastEthernet0/13 and FastEthernet0/14 will continue to pass traffic for VLANs 88，100，360.

A.Switches S1 and S3 will be able to exchange traffic but neither will be able to exchange traffic with Switch S2
B.Switches S1， S2， and S3 will be able to pass traffic between themselves. However， if there is a topology change， Switch S2 will not receive notification of the change.
C.Switches S1， S2， and S3 will be able to pass traffic between themselves.
D.IEEE 802.1D and IEEE 802.1w are incompatible. All three switches must use the same standard or no traffic will pass between any of the switches.

A.Router A is the master virtual router， and Router B is the backup virtual router. When Router A fails， Router B will become the master virtual router. When Router A recovers， Router B will maintain the role of master virtual router.
B.Router A is the master virtual router， and Router B is the backup virtual router. When Router A fails， Router B will become the master virtual router. When Router A recovers， it will regain the master virtual router role.
C.Router B is the master virtual router， and Router A is the backup virtual router. When Router B fails， Router A will become the master virtual router. When Router B recovers， Router A will maintain the role of master virtual router.
D.Router B is the master virtual router， and Router A is the backup virtual router. When Router B fails， Router A will become the master virtual router. When Router B recovers， it will regain the master virtual router role.

A.STP timers values （hello， forward delay， max age） are included in each BPDU.
B.A switch is not concerned about its local configuration of the STP timers values. It will only consider the value of the STP timers contained in the BPDU it is receiving.
C.To successfully exchange BPDUs between two switches， their STP timers value （hello， forward delay， max age） must be the same.
D.If any STP timer value （hello， forward delay， max age） needs to be changed， it should at least be changed on the root bridge and backup root bridge.
E.On a switched network with a small network diameter， the STP hello timer can be tuned to a lower value to decrease the load on the switch CPU.
F.The root bridge passes the timer information in BPDUs to all routers in the Layer 3 configuration.

A.CEF， distributed CEF （dCEF）， fast switching， process switching
B.distributed CEF （dCEF）， CEF， fast switching， process switching
C.fast switching， process switching， distributed CEF （dCEF）， CEF
D.process switching， fast switching， distributed CEF （dCEF）， CEF
E.process switching， distributed CEF （dCEF）， CEF， fast switching
F.process switching， CEF， distributed CEF （dCEF）， fast switching

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.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.All secure addresses will age out and be removed from the secure address list. This will cause the security violation counter to increment.
B.The first address learned on the port will be removed from the secure address list and be replaced with the new address.
C.The interface will be placed into the error-disabled state immediately， and an SNMP trap notification will be sent.
D.The packets with the new source addresses will be dropped until a sufficient number of secure MAC addresses are removed from the secure address list.