1) If you surf the Internet off campus, the actual IP is generally not the local IP displayed by the computer. For example, if you surf the Internet through broadband, at this time, the IP of broadband connection is the IP you really use to surf the Internet. If you use a router at home, the IP at the exit of the router is the IP where you surf the Internet. What you showed in the question is the IP of your computer itself.

2) If your computer is really on campus and your IP (172.18.13.215) is also on campus, you can definitely visit the library website. If you visit other network resources (such as China HowNet, Wanfang, etc. ) through the school library and show that your IP is an illegal user, it may be that there is a problem with the proxy settings in IE. Please ask the school network administrator how to set up IE agent correctly.

Supplement,

If you are on campus and your supplementary IP is 219.234.81.138, it may just be that you used a proxy in IE. Please check in IE-& gt；; Tools-> Internet options-> Connection tab->; Local area network settings.

You can compare it with your colleagues' settings to confirm it.

Besides, don't tell me that you are on the VPN outside the school, which is different from the school.

According to your supplement,

You'd better look at the settings of your colleague's proxy server again, which is the same as theirs. Your problem should be here.