Server Firewall Error

M

miltongoh

Verified User
Joined
Oct 2, 2005
Messages
50
Location
Singapore
Hi,

The moment I enable IPTABLES, my DNS seems to screwed up and not working while if I disable it, all website DNS is working fine.

Anything I should do to enable it running well?
 
What firewall rules are enabled when starting iptables?
 
Is this wrong?
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 21 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 25 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 42 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 53 -j ACCEPT
Click to expand...

Have I missed out something?
 
Are there any OUTPUT rules or is is it set to allow all OUTPUT traffic?
 
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 2222 -j ACCEPT
Click to expand...

This added.

The full file is.

# Firewall configuration written by system-config-securitylevel
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A FORWARD -j RH-Firewall-1-INPUT
-A RH-Firewall-1-INPUT -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -p icmp --icmp-type any -j ACCEPT
-A RH-Firewall-1-INPUT -p 50 -j ACCEPT
-A RH-Firewall-1-INPUT -p 51 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp --dport 5353 -d 224.0.0.251 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp -m udp --dport 631 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 21 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 25 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 42 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 53 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 2222 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 8080 -j ACCEPT
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
COMMIT
Click to expand...

Does this seems to be a problem? I can't find my DNS working after getting IPTABLES up running. :(
 
For DNS port 53 needs to be open for both inbound and outbound, for both udp and tcp/ip traffic.

Search these forums for the kiss firewall; it's a simple to install script that will manage iptables for you.

Jeff
 
jlasman said:
For DNS port 53 needs to be open for both inbound and outbound, for both udp and tcp/ip traffic.

Search these forums for the kiss firewall; it's a simple to install script that will manage iptables for you.

Jeff
Click to expand...

Hi Jeff,

Thanks for the pointer!
 
Last edited:
Also APF Firewall w/BFD is quite simple to install and will configure iptables for you.
 
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