Firewall problems
 

Dear people,

As my user name suggest, I’m very new with Linux I’m using Fedora Core 2.

I have some problems with the firewall, when it is active, it look that the firewall is blocking all outgoing data.

I have also Firestarter installed, but this also not gives me a clear idea what is incoming and outgoing data. Basically I want that the firewall allows all data outgoing and block some incoming ports.

I’m using a 56K analog modem on serial port 1.

With kind regards

Richard

here is a very simple script

#!/bin/sh
# Simple firewall script
iptables -X
iptables -F
iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP

iptables -A OUTPUT -o lo -j ACCEPT
iptables -A INPUT -i lo -j ACCEPT

iptables -A OUTPUT -o ppp -j ACCEPT -m state --state NEW,RELATED,ESTABLISHED
iptables -A INPUT -i ppp -j ACCEPT -m state --state RELATED,ESTABLISHED

Hello PPuru,

I'm very happy with this simple script, but there is a small problem. The small problem is that I have no idea what to do with this simple script.

Therefore I want to ask if you can explain it to in some more details?

With kind regards,

Richard

name that script to something like firewallrules.sh and save it to /etc/rc.d

Login as root

save that script as say ... simpfilt.sh in your /root directory.

from your /root directory

#chmod 700 simpfilt.sh
#mv /etc/sysconfig/iptables /etc/sysconfig/iptables.orig
#source simpfilt.sh
#service iptables save

now you have the script running

#iptables -nvL

to will give you the current ruleset.

Dear Ppuru and Sporadic235,

Thanks for the information; I can now connect to the internet with my Firewall running.

As all things in live, one solution for a problem opens the way for new problems. I’m using a Micronet SP3000 56k External modem (serial RS-232). I use KPPP to dial to my ISP, KPPP informs me that I’m connect at 52000 but it takes ages to get a website or if I try to download some files it never gets above 0.6kb download speed.

With my Windows 2000 computer, I use the same modem and get easily 4.4 to 5.2 kb download speed.

It is also almost clockwork that I get disconnected from the internet after +/- 2 hours, if I get not disconnected after 2 hours I not receive any data from my ISP after 2 hours time. My ISP told me that the problem is at my side; I have to say I use the same ISP for my Windows system and not have problems like that.

I think that this is not a firewall problem, as the same happens with Firewall On or Off.

If somebody, knows something that a newbie :study: surely forget to do when he installed his modem, I did not that much. KPPP “Wizzard” and ISP user information…..

With kind regards,

Richard