HTTP protocol using TCP communication, the default port is

IPv4 addresses consist of 32 bit, usually in dotted decimal form, such as 11.110.96.132. In addition, IP address 11.110.96.132 can also be expressed as follows

The client has an error accessing the FTP server. If there is no problem checking the connectivity between the server and the client, then which servers are possible?
Is the port blocked? (choose 2 answers)

Which of the following error messages can provide information and handling of IP packets to the source?

The two routers are running on the PPP link. The administrator has configured OSPF single areas on both routers, and their router IDs are the same.
The correct description below is ().