Web server cannot be accessed from other clients on Internet

Web server cannot be accessed from other clients on Internet

Post by XIP » Sat, 22 Dec 2001 02:21:52



Hi,

I have setup Linux (with 2 NICs) as a router, my eth1 use the Virtual IP
192.168.1.1
and the other eth0 get its IP by connecting to the Internet through PPPOE.

I have setup firewall using iptables, allowing ports like  21,80 connection
from outside.
FTP works perfect from outside, inside or the Linux itself.

I have also setup a web server on the Linux. I can access it by IP address
(e.g. http://203.123.1.1)
(using the IP assigned by ISP through DHCP/PPPOE) by using a browser
on my internal LAN or on my Linux.
However, it cannot be accessed from other clients on the Internet.
Do anyone have any ideas why?

N.B. outside can ping or FTP to my Linux, but web access fail.
I haveever disbled the firewall but my web server still could not be
accessed from outside.

Simon

 
 
 

Web server cannot be accessed from other clients on Internet

Post by Karl Heye » Sat, 22 Dec 2001 03:15:44


...

Quote:> (using the IP assigned by ISP through DHCP/PPPOE) by using a browser
> on my internal LAN or on my Linux.
> However, it cannot be accessed from other clients on the Internet.
> Do anyone have any ideas why?

> N.B. outside can ping or FTP to my Linux, but web access fail.
> I haveever disbled the firewall but my web server still could not be
> accessed from outside.

run a tcpdump -n -i ppp0
and try and connect to the web server from outside.  For it to work
to should see packets appearing in the tcpdump output. The IPs
involved will be the outside IP your connecting from and the IP of
the box.

I suspect your provider maybe blocking port 80 access to your
system, if that is the case then no packets will appear in tcpdump
and you will have to contact the provider and tell them your not
running IIS (ie the reason why it is blocked).

karl.

 
 
 

Web server cannot be accessed from other clients on Internet

Post by XIP » Sun, 23 Dec 2001 01:15:20


Karl,

You are completely correct!  My ISP blocked port 80.
I have tried tcpdump and found nothing of port 80 getting in from outside,
later I change the web server port to some non-standard port,
then access my web server from other client  from the Internet , it worked!

Thanks a lot.

Simon




> ...
> > (using the IP assigned by ISP through DHCP/PPPOE) by using a browser
> > on my internal LAN or on my Linux.
> > However, it cannot be accessed from other clients on the Internet.
> > Do anyone have any ideas why?

> > N.B. outside can ping or FTP to my Linux, but web access fail.
> > I haveever disbled the firewall but my web server still could not be
> > accessed from outside.

> run a tcpdump -n -i ppp0
> and try and connect to the web server from outside.  For it to work
> to should see packets appearing in the tcpdump output. The IPs
> involved will be the outside IP your connecting from and the IP of
> the box.

> I suspect your provider maybe blocking port 80 access to your
> system, if that is the case then no packets will appear in tcpdump
> and you will have to contact the provider and tell them your not
> running IIS (ie the reason why it is blocked).

> karl.

 
 
 

1. RH6.0 web server cannot be accessed from Internet

I have a new RH6.0 installation running Apache 1.3.6.  I am able to connect
to it fine across my LAN, browsing the web pages without problem.  But, I
cannot access it from the Internet (I tried at a friend's place, then I just
signed up for the AOL trial and I cannot connect).  But, my previous
computer, which is running RH5.2 with the same Apache, it accessible from
the Internet.  I can connect out to the Internet fine from the RH6.0 box
(using Netscape, I can connect anywhere I want).

Is there some security option in RH6.0 that is blocking the HTTP/FTP
packets?

The only thing I see different so far is that my RH5.2 box and the RH6.0
have different output from netstat -r.

The 5.2 box (which works fine) shows three entries, one for the loopback,
one for default, and one for my gateway address.

But 6.0 shows an additional entry which includes as a 'destination' the
box's IP address, with a netmask that is fully specified as 255.255.255.255
on my eth0 interface.  Is that a problem?

Any help would be appreciated, since the reason for the upgrade was to have
a better web server, and instead it cannot be used yet!

Thanks,
David
myEastside.com

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