As shown in the network, SWA and SWD enable RSTP, but SWB and SWC do not enable spanning tree protocol, the following statements are correct:

• A. When the SWB port E0/2 is down, the SWD port E0/2 will become the new root port and immediately enter the forwarding state
• B. When the SWB port E0/2 is down, the SWD port E0/2 will wait 3 Hello Time before it becomes the new root port and enters the forwarding state
• C. SWD will have a port role as Alternate
• D. Because SWB and SWC do not enable spanning tree protocol, when the root port of SWD is down, the alternate port cannot immediately become the new root port and enter the forwarding state

Which of the following descriptions about remote port mirroring are correct?

• A. The reflection port of remote port mirroring is essential
• B. Remote port mirroring must include the mirror source and destination switch
• C. The ProbeVLAN of remote port mirroring should prohibit MAC address learning

The customer's LAN switch SWA is connected to SWB through Gigabitthem 2/0/1, and to SWC through GigabitEthernet 2/0/2, and the S\NA switch has the following configuration:
[SWA]smart-link group 1
[SWA-smlk-group1 ]protected-vlan reference-instance 0 to 32
[SWA-smlk-group1]port gigabitethernet 2/0/1 slave
[SWA-smlk-group1]port gigabitethernet 2/0/2 master
[SWA-smlk-group1 ]flush enable control-vlan 10
If the interconnection interfaces of switch SWA, switch SWB, and switch SWC allow all VLANs to pass, you can know from the above information

• A. If the Gigabitethernet 2/0/1 port fails, the SWA switch will broadcast flush packets in all VLANs
• B. If the Gigabitethernet 2/0/2 port fails, the SWA switch will broadcast flush packets in all VLANs
• C. Under normal circumstances, SWA switch traffic will be uplinked through Gigabitethernet 2/0/1
• D. Under normal circumstances, SWA switch traffic will be uplinked through Gigabitethernet 2/0/2

In the networking shown in the figure, the PIM SM protocol runs between RT1, RT2 and RT3, the RP is 1.1.1.1 RT3 is connected to the receiver, and IGMP is enabled on the corresponding interface, and the multicast source 2.2.2.2 is connected View the unicast routing table on RT2 on RT3 as follows:
[RT3]display ip routing-table
Routing Tables: Public
Destinations: 11 Routes: 12
Destination/MaskProtoPreCost NextHop Interface
1.1.1.1/320SPF 10 1562 192.168.2.1 so/2/1
2.2.2.2/320SPF 10 1562 192.168.2.1 so/2/1
127.0.0.0/8 Direct 00127.0.0.1 InLoopO
127.0.0.1/32Direct 00127.0.0.1 InLoopO
192.168.0.0/30Direct 00192.168.0.2 S0/2/0
192.168.0.1/32Direct 00192.168.0.1 S0/2/0
192.168.0.2/32Direct 00127.0.0.1 InLoopO
192.168.1.0/300SPF 10 3124 192.168.2.1 so/2/1
OSPF 10 3124 192.168.0.1 S0/2/0
192.168.2.0/30Direct 00192.168.2.2 so/2/1
192.168.2.1/32Direct 00192.168.2.1 so/2/1
192.168.2.2/32Direct 00127.0.0.1 InLoopO
Then, when the receiver (Receiver) sends a group join request, which of the following routers have (*, G) entries

• A. RT3
• B. RT2
• C. RT1

The host PCA, PCB and PCC are respectively connected to the GigabitEthernet1/0/1 port of the switch SWA UP, Ethernet1/0/2 and Ethernet1/0/3 ports, and their addresses are in the same network segment, i exchange & SWA are configured
[SWA]vlan 10
[SWA-vlan10]port ethernet 1/0/1
[SWA-vlan10]quit
[SWA]vlan 20
[SWA-vlan20]port ethernet 1/0/2
[SWA-vlan20]quit
[SWA]vlan 30
[SWA-vlan30]port ethernet 1/0/3
[SWA-vlan30]quit
[SWA]interface ethernet 1/0/1
[SWA-Ethernet1/0/1]port link-type hybrid
[SWA-Ethernet1 /0/1] port hybrid vlan 10 30 untagged
[SWA-Ethernet1/0/1]quit
[SWA]interface ethernet 1/0/2
[SWA-Ethernet1/0/2]port link-type hybrid
[SWA-Ethernet1 /0/2]port hybrid vlan 20 30 untagged
[SWA-Ethernet1/0/2]quit
[SWA]interface ethernet 1/0/3
[SWA-Ethernet1/0/3]port link-type hybrid
[SWA-Ethernet1 /0/3]port hybrid vlan 10 20 30 untagged
-Can judge __ (choose one or more) based on the above information

• A. Intercommunication between PCA and PCC
• B. The configuration command is incorrect
• C. Intercommunication between PCA and PCB
• D. Two PCs cannot communicate with each other
• E. PCB and PCC can communicate directly