greetings all ,

i am new user for linux , i want to setup my linux server to be the firewall of my network .

i use redhat 9 , when i installed it i choosed no firewall .

now i don't have a file /etc/sysconfig/iptables , is that normal ?
should i create it to enable the iptables commands to work ???

i know i have 3 built in chains , and i guess i know the use of every one , but what if i created a new one . when it will be used ??

i guess input chain just used when a packet arrived to the station , so what if i made a chain and named it as " linux " , when this one will be used ?

please help

Hello.


I have a firewalling router which is running SuSE and several desktop computers running Gentoo. On neither of them I have a file called /etc/sysconfig/iptables. I would say that this is a RedHat-only thing so I can't really help you there.

I might be wrong but i _guess_ that for an iptables firewall to work (in general) you don't need this file as there are ways to add rules to the chains (read man iptables). Only if you intend to use the firewall that comes with RedHat you might need it. But I'm sure you can install it with RedHat's package manager or with its configuration program.

If you just want to make a 'simple' firewall for your home network you might as well only use the three built-in chains. The way I see it the possibility to make custom chains is for much more complicated and sophisticated firewalls. Those custom chains will only be used if you add a rule to one of the three standard chains that 'send' a packet to this chain. To do this you can set a rule's target to the name of your chain.

For example instead of -j DROP you would type -j LINUX if your custom chain was called LINUX. Then the rules of the LINUX chain will be applied to the packet.

My dear friend

first of all check whether iptables service is on for that runlevel if it is not ononby giving command

chkconfig --level 3 iptables on

service iptables restart

this should create file in /etc/sysconfig/iptables

also ip_forward should be enable in kernel to work your firewall


try this out........

regards
Manya

About the channels i suggest to read the tutorials on iptables official page:

www.netfilter.org

Those tutorials are short and straight to the point.

Dear All,

thanks so much for your kindly help

really thanks so much .

Be well .