If a port running STP in the Ethernet switch receives and forwards data, receives, processes and sends BPDUs, and performs address learning, then the port should be in the ______ state.

It is required to set a subnet mask to divide a class B network 172.16.0.0 into seven subnets, and each subnet should contain as many hosts as possible, so the subnet mask should be _____. (Dotted decimal format) slightly

Which of the following levels does the TCP/IP protocol stack include? (multiple choice)

Two empty-configured MSR routers are interconnected back-to-back through their respective GE0/0 interfaces, and their interconnection network segment is 192.168.1.0/30. After the IP addresses are correctly configured, the GE0/0 interfaces of the two routers can communicate with each other. Now the following OSPF configurations are added to the two routers:
ospf 1
area 0.0.0.1
network 192.168.1.0 0.0.0.3
So which of the following statements are correct?

UDP belongs to the ______ of the OSI reference model.