apache not accepting incoming connections from outside of localhost

Phildo picture Phildo · May 24, 2012 · Viewed 155.6k times · Source

I've booted up a CentOS server on rackspace and executed yum install httpd'd. Then services httpd start. So, just the barebones.

I can access its IP address remotely over ssh (22) no problem, so there's no problem with the DNS or anything (I think...), but when I try to connect on port 80 (via a browser or something) I get connection refused.

From localhost, however, I can use telnet (80), or even lynx on itself and get served with no problem. From outside (my house, my school, a local coffee shop, etc...), telnet connects on 22, but not 80.

I use netstat -tulpn (<- I'm not going to lie, I don't understand the -tulpn part, but that's what the internet told me to do...) and see

tcp    0    0 :::80     :::*    LISTEN    -                   

as I believe I should. The httpd.conf says Listen 80.

I have services httpd restart'd many a time.

Honestly I have no idea what to do. There is NO way that rackspace has a firewall on incoming port 80 requests. I feel like I'm missing something stupid, but I've booted up a barebones server twice now and have done the absolute minimum to get this functioning thinking I had mucked things up with my tinkering, but neither worked.

Any help is greatly appreciated! (And sorry for the long winded post...)

Edit I was asked to post the output of iptables -L. So here it is:

Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     all  --  anywhere             anywhere            state RELATED,ESTABLISHED 
ACCEPT     icmp --  anywhere             anywhere            
ACCEPT     all  --  anywhere             anywhere            
ACCEPT     tcp  --  anywhere             anywhere            state NEW tcp dpt:ssh 
REJECT     all  --  anywhere             anywhere            reject-with icmp-host-prohibited 

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         
REJECT     all  --  anywhere             anywhere            reject-with icmp-host-prohibited 

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination   

Answer

antonio.fornie picture antonio.fornie · Oct 24, 2013

In case not solved yet. Your iptables say:

state RELATED,ESTABLISHED

Which means that it lets pass only connections already established... that's established by you, not by remote machines. Then you can see exceptions to this in the next rules:

state NEW tcp dpt:ssh

Which counts only for ssh, so you should add a similar rule/line for http, which you can do like this:

state NEW tcp dpt:80

Which you can do like this:

sudo iptables -I INPUT 4 -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT

(In this case I am choosing to add the new rule in the fourth line)

Remember that after editing the file you should save it like this:

sudo /etc/init.d/iptables save