My previous problem solved itself, but it led to another problem. I entered the domain name www.tp5.com:82 in the address bar before, but the browser showed that it could not be displayed. I reset the port number and changed the port number of the domain name www.tp5.com to 80 and everything became normal. Port 80 was already used when I was learning PHP. Now I have reset it and left port 80 for the domain name www.tp5.com and it is normal. However, when the previous domain name was changed to another port number, the browser cannot display it. . So now I can use port 80 normally, but other ports cannot be used normally. I use win10 system. Why can't other ports be displayed normally? Ask the experts!