Apache2 does not run on IPv4 tcp port

Question

I need run Apache2 on my Debian 7 server. But it run only on tcpv6 port, not on tcpv4 port. I installed it with apt-get install. If I go to localhost or 127.0.0.1 or my server IPv4 address it does not display any website.

My /etc/apache2/ports.conf:

# If you just change the port or add more ports here, you will likely also
# have to change the VirtualHost statement in
# /etc/apache2/sites-enabled/000-default
# This is also true if you have upgraded from before 2.2.9-3 (i.e. from
# Debian etch). See /usr/share/doc/apache2.2-common/NEWS.Debian.gz and
# README.Debian.gz

NameVirtualHost *:80
Listen 80

<IfModule mod_ssl.c>
 # If you add NameVirtualHost *:443 here, you will also have to change
 # the VirtualHost statement in /etc/apache2/sites-available/default-ssl
 # to <VirtualHost *:443>
 # Server Name Indication for SSL named virtual hosts is currently not
 # supported by MSIE on Windows XP.
 Listen 443
</IfModule>

<IfModule mod_gnutls.c>
 Listen 443
</IfModule>

netstat -plntu:

tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      3558/sshd       
tcp        0      0 0.0.0.0:3466            0.0.0.0:*               LISTEN      2820/mysqld     
tcp6       0      0 :::80                   :::*                    LISTEN      2097/apache2    
tcp6       0      0 :::22                   :::*                    LISTEN      3558/sshd       

Answer 1

The fact that netstat shows only tcp6 here is not the problem. If you don't specify an address to listen on, apache will listen on all supported address families using a single socket (for design reasons, sshd uses a unique socket per address & address family, hence showing up twice in your netstat output).

Here's one of my systems, showing apache having only tcp6 sockets, and yet still working fine via both IPv4 and IPv6.

woodpecker ~ # netstat -anp |grep apache
tcp6       0      0 :::80    :::*       LISTEN      1637/apache2        
tcp6       0      0 :::443   :::*       LISTEN      1637/apache2        
woodpecker ~ # wget http://127.0.0.1/ -O /dev/null
--2013-12-25 08:52:38--  http://127.0.0.1/
Connecting to 127.0.0.1:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 45 [text/html]
...
# wget http://[::1]/ -O /dev/null
--2013-12-25 08:53:00--  http://[::1]/
Connecting to [::1]:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 45 [text/html]
...

If you run wget http://127.0.0.1/ -O - on the server what happens? Does it successfully connect? Does it return the raw HTML for your website as expected?

Answer 2

This will handle IPV4 connections only:

Listen 0.0.0.0:80
Listen 192.0.2.1:80 

https://httpd.apache.org/docs/2.2/bind.html#ipv6

Answer 3

1. 127.0.0.1 is local to a machine only, you have to be on the server itself in a browser to use the local loopback ip/address;

2. You might have a firewall blocking ports;

3. Make sure apache is running and working properly, check error logs;

4. Double check all your apache configs;

5. Are you hosting from the root www or the user public_html directory?

6. Double check owner and permissions.

---

Almost the year 2019 (Welcome to the future):

• By default most of the world uses ipv6 and if fails, falls back on ipv4;

• We now have ipv4 tunnels over ipv6, and vise-versa;

• Most OS, programs, client, and server alike mostly do this now;

• Welcome to the world of no more NATs and having to depend now on firewall/filters right to your device;

• I would recommend trying to keep your systems all dual stacked, supporting both ipv4 and ipv6 at the same time, so when the magic switch happens, you're still up and running. My OS, network, even my ISP is dual stacked end to end. I could turn off ipv4 fully if I wanted to, but what's out there that might not work anymore if no tunnels exist back to ipv6 from ipv4.

Answer 4

*

wget http://127.0.0.1/ -O /dev/null

* represents connection to local server without handling IPv4 or IPv6, if you change localhost (or 127.0.0.1) to real IPv4 IP address of this server, you cant wget anything because denied connection.

Try to describe you IP in config files: NameVirtualHost :80 Listen :80