When a company's network management needs to plan the network, the data packets that allow PC1 to access PC2 go through the G0/0/0 port (G0/0/2 on the picture). The data packet that PC2 accesses to PC1 goes from port G0/0/4 (G0/0/0 in the picture). () (Single-choice question)

In RSTP, an edge port becomes a common STP port after receiving a configuration BPDU.

UDP is connectionless and must rely on () to ensure the reliability of transmission.

The Backup port in RSTP can replace the failed root port.

Which of the following interfaces are not open to Huawei controllers?