Ttgjyuk

please nginx in my server did start please follow me

root@s45-****:/home/arabico# nmap 45.****

PORT STATE SERVICE
22/tcp open ssh
5/tcp open smtp
80/tcp open http

Nmap done: 1 IP address (1 host up) scanned in 0.06 seconds
root@s45-****:/home/arabico# sudo service apache2 stop
 * Stopping web server apache2 * 
root@s45-****:/home/arabico# nmap 45.****

Starting Nmap 6.40 ( http://nmap.org ) at 2015-06-05 19:33 MST

PORT STATE SERVICE
22/tcp open ssh
25/tcp open smtp

Nmap done: 1 IP address (1 host up) scanned in 0.06 seconds
root@s45-***:/home/arabico# sudo service nginx restart
 * Restarting nginx nginx 
 [fail] 


root@s45-***:/home/arabico# nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: [emerg] socket() [::]:80 failed (97: Address family not supported by protocol)
nginx: configuration file /etc/nginx/nginx.conf test failed

root@s45***:/home/arabico# sudo nginx
nginx: [emerg] socket() [::]:80 failed (97: Address family not supported by protocol)

how to let it start please

nginx: [emerg] socket() [::]:80 failed (97: Address family not supported by protocol)

From the error message this seems ipv6 is disabled on your server.
Edit nginx default server configuration and changed it to listen on ipv4 only or enable ipv6.

listen 80 default_server;
# comment to disable ipv6
# listen [::]:80 default_server;

just i deleted this line

listen [::]:80 default_server ipv6only=on;

from

/etc/nginx/sites-available/default
and it works :D

Thanks for mentioning ipv6.

In my case, I got a line in nginx conf of

proxy_pass http://localhost:3028/;

The problem happened when I disable ipv6 in the kernel config. Reenabling ipv6 can solve the problem, but it is not what I want.

the solution is delete

::1 localhost ip6-localhost ip6-loopback
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

in /etc/hosts.

so the localhost will alway follow the default ipv4 target, which is 127.0.0.1.

Just deleting the ::1 line could be enough. Since ipv6 is totally disabled, I would delete all of them.

Changing the localhost in nginx config to 127.0.0.1 may solve this problem as well.