Dear All,

I want to assign variables in iptables file.(/etc/sysconfig/iptables) generated by iptables-save script. But its not working.
Following is my iptables file. and OS is Centos.

##################################
*filter
:INPUT ACCEPT [189:21747]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [174:24924]
Jesse="73.185.155.233"
rmrg="23.24.136.233"
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 811 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 25 -j ACCEPT
-A INPUT -p tcp -m tcp -s $Jesse -j ACCEPT
-A INPUT -p udp -m udp -s $Jesse -j ACCEPT
-A INPUT -p tcp -m tcp -s $rmrg -j ACCEPT
-A INPUT -p udp -m udp -s $rmrg -j ACCEPT
-A INPUT -p tcp -m tcp -j DROP
-A INPUT -p udp -m udp -j DROP
COMMIT
##############################

Please help. What is correct way of assigning variables in iptables file.

Regards.
Kamran

As far as I know you need to use a bash script to load rules based on variables. There are many examples that can be found on the net.

Dear michaelk,

Can you please guide me about any link for bash script of iptables which is tested one.
I have already tried one with script but failed.

Regards,
Kamran

What have you tried?

http://wiki.centos.org/HowTos/Network/IPTables
http://www.cyberciti.biz/faq/rhel-fe...ation-tutorial

Dear michaelk,

I have tried this script before. Issue with my script is when ever I activate my script, my SSH connection goes down.
I think below default policies don't let my traffic to go pass through my ssh traffic.

iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT


Can you please help if I am wrong or right on this? A workaround which I have done to clear this situation is I rebooted my machine physically and then firewall script stopped automatically and I am able to ssh my machine.

regards,
Kamran

From post #3's first link:

Dear ilestrg,

Don't u think that "iptables -P INPUT ACCEPT" will accept all incoming traffic.
Because iptables rules run by their order. Rules for incoming traffic under this must not be worthable after this.

Am i right or wrong?

regards,
Kamran Ayub

With drop as the default policy you need to add rules for input and output. Having a default policy as accept and then as the last rule drop everything in the end works the same.