Which of the following reasons may cause the hosts in the same--VLAN LAN to fail to communicate with each other

By executing the () command, users on different ports of the same VLAN can be completely isolated at Layer 2 and Layer 3 and cannot communicate. (Please use English lowercase letters to complete the command, and the command cannot be abbreviated)

Which of the following statements about VLAN aggregation is correct? (Multiple choice)

A router Network LSA is shown in the figure. Which of the following statements is correct? (Multiple choice)

In the DU label distribution mode, if the Liberal retention mode is adopted, the device will retain all the labels distributed by the LDP Peer, regardless of whether the LDP Peer is the optimal next-hop to reach the target network segment.