Strange port 80 access problem

[Beech Rintoul]

On Wednesday 12 September 2007, Don O'Neil said:
> I have a very strange access problem that just popped up this
> morning. For whatever reason, my machine at home over my cable
> modem can no longer access Apache on port 80... However other
> services are accessible elsewhere (Direct Admin control panel, FTP,
> SMTP,etc...) BUT Apache is accessible to other devices, not on my
> IP... It seems as though there is some sort of IP block on me, but
> I can't seem to find anything in the logs to confirm this. I don't
> have a 'deny from' in any .htaccess files... What could be going
> on?
>
> I'm running apache 1.3.39, and FreeBSD 6.1.

It's very possible that your ISP is blocking port 80. It seems more 
and more of them are doing that with home subscribers. I know someone 
who has service with one of the large telcos and they not only block 
port 80, but mail and ftp as well. They told him if he wanted to run 
servers he would have to subscribe to business service at 5X the cost 
of residential.

If you can ping other ports on your home machine, that's most likely 
what's happening. Your logs wouldn't necessarily show anything 
because the requests are not reaching your server. After you verify 
(from outside) that you can't reach port 80, about your only other 
option is to use one of the free nameservers that will redirect your 
traffic to another port. You will also need to reconfigure apache to 
listen on that port instead of port 80. Finally, if you have a 
firewall on your box, make sure it's not getting blocked there.

Verify that apache is actually listening on 80 by doing:

sockstat | grep httpd

You should see lines like the following:

www      httpd      59775 3  tcp46  *:80                  *:*

If you don't than that's your problem, but if you see the *:80, you 
need to contact your ISP, fix your firewall, or look into redirect.


Beech


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Beech Rintoul - FreeBSD Developer - beech at FreeBSD.org
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