The customer LAN switches SWA, SWB, and SWC form the RRPP ring main ring 1, and the switch SWA has the following configuration information:
[SWA] rrpp domain 1
[SWA-rrpp-domain1] control-vlan 4092
If the switch SWA ports Gigabitethernet 1/0/1 and Gigabitethernet 1/0/2 are connected to the RRPP ring, we can know from the above information

As shown in the networking, SWA and SWC enable STP, SWC is the root, SWB does not enable STP, initially Link 2 is not connected, PCB can send data to PCA, if Link 1 fails at this time, maintenance personnel will link 2 is connected, the statement about the recovery process of the PCB to PCA data transfer service is correct (assuming that the PCA will not actively send data)

Regarding MSTP, the correct statement is

As shown in the networking, SWB and SWC enable STP, SWC is the root, SWA does not enable STP, initially Link 2 is not connected, PCB can send data to PCA, if Link 1 fails at this time, maintenance personnel will link 2 is connected, the statement about the recovery process of the PCB to PCA data transfer service is correct (assuming that the PCA will not actively send data)

In the networking shown in the figure, the interconnection lines between RT1, RT2, RT3, and RT4 are all 1000M links except the shared Ethernet part which is a 10M link. The OSPF protocol is run to enable routing to communicate with these 4 routers. Both run PIMSM protocol, RP is 1.1.1.1, receivers are connected to the downstream interfaces of RT1 and RT2, and IGMP is enabled on the corresponding interfaces. Then, when the receiver sends a group join request, which of the following routers are connected (*, G) entry exists?