Two routers are connected through a LAN to form a VRRP backup group. The configuration on each interface is as follows:
[RTA-GigabitEthernet1 /0] display this
IP address 192.168.0.252 255.255.255.0
Vrrp vrid 1 virtual-ip 192.168.0.254
[RTB-GigabitEthernet1/0] display this
IP address 192.168.0.253 255.255.255.0
Vrrp vrid 1 virtual-ip 192.168.0.254
what can we learn from the above information?

• A. RTA and RTB cannot elect a master router for the backup group
• B. RTA is the Master router of the backup group
• C. RTA and RTB are both in VRRP Master state
• D. RTB is the Master router of the backup group

As shown in the figure, the switches are all running RSTP. Initially, SWA, SWB and SWC are interconnected. When the topology is stable, SWB and SWD are connected. Which of the following statements are correct? (Multiple choice)

• A. SWB will clear the MAC addresses learned on ports E0/1 and E0/2 and send RST BPDUs with TC set from these two ports.
• B. After receiving the BPDU with TC set, SWC will clear the MAC address learned on port E0/1 and send a RST BPDU with TC set from the port.
• C. After SWA receives the BPDU with TC set, it will clear all MAC address tables and send the RST BPDU with TC set from E0/2.
• D. SWB will send a RST BPDU with TC set within twice the Hello Time.

Which of the following statements about inter-VLAN communication on switches is correct?
(Multiple choice)

• A. After the Layer 2 switch divides the VLANs, hosts in different VLANs can communicate with each other through a router. The method is to connect the router to the switch's Trunk port with one interface, and the router must support the 802.1Q protocol.
• B. After the three-layer switch divides the VLAN, hosts in different VLANs can communicate. The method is to create a virtual three-layer VLAN interface for each VLAN on the three-layer switch. The VLAN interface needs to be configured with the corresponding IP address.
• C. After the Layer 2 switch divides the VLANs, hosts in different VLANs can communicate with each other through the router. The method is that the router has a physical interface and a physical connection to each VLAN.
• D. Hosts in VLANs divided by switches can communicate, but hosts between VLANs cannot communicate with each other.

Which of the following statements about the architecture of SNMP v3 is correct? (Multiple choice)

• A. SNMP applications include command generators, command responders, indication generators, indication receivers, proxy forwarders, etc.
• B. The SNMP engine consists of a scheduler, a message processing subsystem, a security subsystem, and an access control subsystem.
• C. An SNMP Manager has either a generator or a receiver.
• D. An SNMP entity may be both an SNMP Manager and an SNMP Agent.

The figure shows the networking of Smart Link and Monitor Link cascade. The Smart Link group on switch SWH is used as the uplink port of the Monitor Link group on switch SWH, and the peer port of the downlink port of the Monitor Link group is the master port of the Smart Link group on switch SWJ. The uplink SWD and SWE ports of switch SWH are the ports of the Smart Link group. What can we learn from the above information?

• A. If the links of the upstream switches SWD and SWE of switch SWH are both in Down state, the primary port of the Smart Link group of switch SWJ will be switched to the secondary port.
• B. The Smart Link group status of switch SWJ has nothing to do with switch SWH
• C. If the link of switch SWH to switch SWD is down, the master port of switch SWJ Smart Link group will switch to the slave port.
• D. If the link of switch SWH to switch SWE is down, the primary port of the Smart Link group of switch SWJ will switch to the secondary port.