2. There may be something wrong with the network cable or network card of the computer. Suggest going to another dormitory.
3. It may be that you set the DNS server to obtain automatically, but the DNS server address obtained automatically by the campus network is not available or there is no response. If you want to see if there is a problem with the DNS server, you can try logging in first. If you can log in normally, but the browser can't open the web page, you can basically determine that it is the address of the DNS server. If it is the address of the dns server, you can check the address of the telecom DNS server in Baidu's own province and city online.
Campus broadband has error codes, such as error 678. In fact, you can call 10000 to ask what telecommunications is, and they will also provide some suggestions and solutions.