Hi, My knowledge of IP tables is not too great. But I think this example you have given is supposed to represent a flow of related DNS packets between This host, and a DNS server. Correct me if I'm wrong. Now I think your INPUT chain rule is not necessary and should be handled by an INPUT chain where the state is RELATED, or ESTABLISHED. I don't think you Need to specify the INPUT chain rule as you have done, so something like The following is what you want. This accepts any packets in the listed state Which is proper firewall behaviour. Iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT Somebody else might like to add to this, or correct me if necessary. Regards, Geoff. -----Original Message----- From: redhat-list-bounces@xxxxxxxxxx [mailto:redhat-list-bounces@xxxxxxxxxx] On Behalf Of Vivek Mangal Sent: Wednesday, 18 July 2007 5:08 p.m. To: redhat-list Subject: help me in IPTABLES 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 -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list ========================================================== For more information on the Television New Zealand Group, visit us online at tvnz.co.nz ========================================================== CAUTION: This e-mail and any attachment(s) contain information that is intended to be read only by the named recipient(s). This information is not to be used or stored by any other person and/or organisation. -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
