In the process of tearing down the TCP connection as shown in the figure, the Y part of FIN should be filled with ______.

The Ethernet frame exchange on the switch relies on the MAC address mapping table, which can be established by ______. (Multiple choice)

Divide a class C network into subnets. If all 0 and all 1 subnets are not valid subnets, then use a 26-bit mask to subnet the network. The number of effective subnets that can be divided is ______. (Please fill in Arabic numerals)

Which of the following statements about MAC addresses are wrong? (multiple choice)

Execute the following configuration commands on the router:
[Router] dhcp enable
[Router] server forbidden-ip 192.168.1.10
[Router] server forbidden-ip 192.168.1.254
[Router] dhcp server ip-pool 0
[Router-dhcp-pool-0] network 192.168.1.0 mask 255.255.255.0
[Router-dhcp-pool-0] gateway-list 192.168.1.254
[Router-dhcp-pool-0] dns-list 192.168.1.10
[Router-dhcp-pool-0] expired day 5
After completing the above configuration, which of the following statements are correct? (multiple choice)