80 port does not open the site related issues

80 port does not open the site problem
My website suddenly can't open today, can be opened before. Today I checked the next, the port for the other, the website can open. If you use port 80, it is not turned on. At first I thought it was 80 ports occupied, and later found that 80 ports were not occupied. I use the IIS server, later replaced by Apache, or the same situation, 80 port can not open, the other ports to open, I ask you the great God, what is the situation, how to solve it!
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How do you know that port 80 is not occupied?
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Cut a picture and see!
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Netstat-ntlp
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grep 80
Check if the httpd.conf inside Listen is set to 80

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Stop IIS, httpd.conf inside listen plus 80.
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See which one occupies 80, show me is Nginx, and then kill it, 6026 is the PID, restart Apache, and then look at
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The external 80 port address is to be in the network service provider where the record, otherwise it will be blocked
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Is your computer your own local or operator's server?

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