where is the firewall?

[Anthony Christopher]

robert rottermann wrote:
> NoOp schrieb:
>   
>> On 09/16/2009 11:52 AM, robert rottermann wrote:
>>     
>>> first: where is the firewall, how do I configure it?
>>>
>>> iptables -L shows nothing.
>>>
>>> if there is (as I am afraid) no firewall, how is the access from the internet
>>> block (the box is is used as a webserver).
>>>
>>>       
>> $ locate iptables
>> /sbin/iptables
>> etc.
>>
>> If it's not there (should be):
>> http://packages.ubuntu.com/dapper/iptables
>>
>> You may also find these links helpful:
>>
>> <http://ubuntu-tutorials.com/2009/06/03/getting-started-with-firewall-builder/>
>> https://help.ubuntu.com/6.06/index.html
>> [Server Guide - HTML, PDF]
>> https://help.ubuntu.com/6.06/ubuntu/serverguide/C/index.html
>> <https://help.ubuntu.com/6.06/ubuntu/serverguide/C/firewall-configuration.html>
>>
>>
>>
>>     
> thanks for your quick answer
>
> sorry, I was not precise enouth.
> iptables is installed but there are no rules
>
> /sbin/iptables
> iptables v1.3.3: no command specified
> Try `iptables -h' or 'iptables --help' for more information.
> root at ubuntu60664m:~# /sbin/iptables -L
> Chain INPUT (policy ACCEPT)
> target     prot opt source               destination
>
> Chain FORWARD (policy ACCEPT)
> target     prot opt source               destination
>
> Chain OUTPUT (policy ACCEPT)
> target     prot opt source               destination
>
> does that mean, that there i no firewall on this system?
>
> robert
>
>   
It means that the firewall built-in to your operating system is pretty 
much wide open, which with the minimalist ubuntu approach to 
installation may not be as big of a problem as it first sounds.  But 
your previous administrator may have been one of those people who when 
they have something that works, stick to it, Thus they may have 
installed some other firewall that worked for them on a different 
system. Since most firewalls are started on boot-up, you might look 
through the script names in /etc/init.d and read various files like 
/etc/rc.local or the files in the /etc/network file tree to see if any 
of them indicate the startup of a firewall.  It might be simpler though 
to use a program that tests your systems network security and address 
any IP vulnerabilities using an iptables firewall script.