help me in IPTABLES

[Budi Febrianto]

Vivek Mangal wrote:
> hello all,
> 
>   Can you help me to understand iptables Problem in below line
> 
> iptables -A OUTPUT -p udp -o eth0 --dport 53 --sport 1024:65535 -j ACCEPT
> 
> iptables -A INPUT -p udp -i eth0 --sport 53 --dport 1024:65535 -j ACCEPT
> 
> I have confeusion that in first line Destination Port is 53 and Source
> Port 1024
> to 65535
> means any request come from 1024 to 65535 ports goes to 53  port.
> 
> And in second line Destination Port is 1024 to 65535 and Source Port 53
> means any request come from 53 port goes to 1024 to 65535 ports.
> 
> it open all 1024 to 65535 and 53 ports then what the use of Iptable ?
> 
> Please help me........
> 
> Vivek Mangal

you can disregard the INPUT line and put INPUT with ESTABLISHED, RELATED 
instead.
something like
iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT

Budi Febrianto
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