----- Original Message ----- From: Jason Opperisano <opie@xxxxxxxxxxx> Date: Thursday, February 3, 2005 7:48 pm Subject: Re: myrules comment > On Wed, 2005-02-02 at 23:58, varun_saa@xxxxxxxx wrote: > > Hello, > > My server is Mandrake 10.1 > > eth0 is WAN with static IP connected to 512k DSL > > eth1 is LAN. > > > > Basically I want clients to able to : > > > > 1. send and recieve mails > > internal users sending mail: > > iptables -A FORWARD -i eth1 -o eth0 -p tcp --syn \ > --sport 1024: --dport 25 -j ACCEPT > > internal users receiving mail via pop3: > > iptables -A FORWARD -i eth1 -o eth0 -p tcp --syn \ > --sport 1024: --dport 110 -j ACCEPT > > > 2. browse the net through squid > > internal users connecting to squid: > > iptables -A INPUT -i eth1 -p tcp --syn \ > --sport 1024: --dport 3128 -j ACCEPT > > squid proxy fetching content from the internet: > > iptables -A OUTPUT -p udp \ > --sport 1024: --dport 53 -j ACCEPT > > iptables -A OUTPUT -o eth0 -p tcp --syn \ > -m owner --uid-owner squid \ > --sport 1024: --dport 80 -j ACCEPT > > > 3. Use MSN or Yahoo > > msn: > > iptables -A FORWARD -i eth1 -o eth0 -p tcp --syn \ > --sport 1024: --dport 1863 -j ACCEPT > > yahoo: > > iptables -A FORWARD -i eth1 -o eth0 -p tcp --syn \ > --sport 1024: --dport 5050 -j ACCEPT > > > My iptables config is as follows : > > > > # Generated by iptables-save v1.2.9 on Thu Oct 21 05:32:36 2004 > > *nat > > :OUTPUT ACCEPT [0:0] > > :PREROUTING ACCEPT [0:0] > > :POSTROUTING ACCEPT [0:0] > > -A POSTROUTING -o eth0 -j MASQUERADE > > COMMIT > > # Completed on Thu Oct 21 05:32:36 2004 > > # Generated by iptables-save v1.2.9 on Thu Oct 21 05:32:36 2004 > > *mangle > > :PREROUTING ACCEPT [32056:3889577] > > :INPUT ACCEPT [32010:3885659] > > :FORWARD ACCEPT [0:0] > > :OUTPUT ACCEPT [31637:4617585] > > :POSTROUTING ACCEPT [31639:4618071] > > COMMIT > > # Completed on Thu Oct 21 05:32:36 2004 > > # Generated by iptables-save v1.2.9 on Thu Oct 21 05:32:36 2004 > > *filter > > :FORWARD DROP [0:0] > > :INPUT DROP [0:0] > > :OUTPUT ACCEPT [0:0] > > -A INPUT -j ACCEPT > > every INPUT rule after this is ignored, as you have just accepted all > packets, > > > -A INPUT -s 127.0.0.1 -j ACCEPT > > -A INPUT -p tcp -m tcp -i eth1 --dport 3128 -j ACCEPT > > -A INPUT -p udp -m udp -i eth1 --dport 3128 --sport 80 -j ACCEPT > > -A INPUT -s 62.0.0.0/255.0.0.0 -i eth0 -j REJECT > > -A INPUT -p tcp -m tcp -s 217.81.0.0/255.255.0.0 -i eth0 -j REJECT > > -A INPUT -i eth0 -j DROP > > -A INPUT -p tcp -m tcp -i eth1 --sport 80 -j DROP > > -A INPUT -m state -i eth1 --state ESTABLISHED,RELATED -j ACCEPT > > -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT > > excellent. > > > -A FORWARD -i eth1 -o eth0 -p tcp --syn --sport 1024 --dport 25 - > j ACCEPT > > -A FORWARD -i eth1 -o eth0 -p tcp --syn --sport 1024 --dport 110 - > j ACCEPT > > those rules will only match packets that have a source port of exactly > 1024--which won't be many packets. i think you mean "1024:" > > -j > >Yes that was a typo error. Thanks a lot for your inputs. I trying to understand. Varun
