Which state does the 0SPF protocol use to indicate that the adjacency relationship has been established? ()

What kind of message does the DHCP server use to confirm that the host can use the IP address? ()

The output information of the sub-interface of a certain router's aggregation port 1 is shown in the figure. Based on this information, which of the following statements is correct? ( )
[Router A] display Interface Eth-Trunk 1.100Eth-Trunk1.100 current state UP Line protocol current state UP Last line protocol up time 2019-03-04 10:22:40 UTC.-08:00 Description: HUAWEI, ARSeries, Eth-Trunk1.100 Interface Route Port, Hash arithmetiC.:According to SIP-XOR-DIP, Maximal BW:2G.Current BW:2G, The Maximum Transmit Unit is 1500 Internet Address is 10.0.12.2/24 IP Sending Frames'Format is PKTFIT ETENT 2, Hardwareaddress 1s 00e0-fc3b-2015 Current system time:2019-03-04 10:24:29-08:00 Last 300 seconds input rate0 bits/sec.0 packets/sec Last 300 seconds output rate 0 bits /seC.0 packets/sec Realtime 0 seconds inputrate 0 bits/seC.0 packets/sec Realtime 0 seconds output rate 0 bits/seC.0 packets/sec Input: 6 packets, 574 bytes, Output: 7 packets, 638 bytes, Input bandwidth utilization 0% Output bandwidth utilization 0% PortName Status Weight GigabitEthernet0/0/1 UP 1 GigabitEthernet0/0/2 UP 1 The Number of Ports in Trunk:2 The Number of UP Ports in Trunk:2*

As shown in the figure, two switches use the default parameters to run STP root primary; Switch B uses the configuration command STP priority 0. Then which port will be blocked? () (Single-choice question)

STA. Before associating to AP, it needs to obtain SSID through some message exchange. What are these messages? ()