Listen The 443 Port.md

Listen The 443 Port

When I was debugging, I closed the process that occupied port 443 according to the online tutorial which said the wss service have to use port 443. Then it cause error when accessing file on my server. I have to say I can easily access the file before.

Check the 443 port

On another computer terminal

telnet xxx.xx.xx.xx 443

Found that port 443 is unreachable.

Check the server security group

Find the security group under the list of cloud servers, open the 443 channel in the inbound direction.

Check the firewall

Ubuntu comes with a much simpler firewall configuration tool than iptables in its distribution: ufw

apt-get install ufw

Use ufw to open port 443

ufw allow 443

Now port 443 can be talented, but there is nothing under netstat -antp | grep 443, According to common sense, information containing 0.0.0.0:443 should be displayed, which means this port is being monitored.

Check apache configuration

Now the 443 port is opened but still not being listened. Check the apache configuration files under /etc/apache2/sites-available, I found Listen 443 in file. And I configured apache by Certbot, the configuration had no problem.

Violent resolution

I had no choice

sudo /etc/init.d/apache2 restart

Then

sudo Isof -iTCP -sTCP:LISTEN -P

I saw apache2 9785 www-data 4u IPv4 448556 0t0 TCP *:443 (LISTEN)

Problem solved～