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Hello all. I’m using iptables on RH 8.0
to route and firewall my cable connection to the rest of the lan. My problem is joining games (Ghost Recon) on
ubi.com from behind the firewall. Ubi.com
requires port 80 for http which works fine, port 6667 for chat which also works
fine, and 40000-42000 for the game (I’m assuming) which seems to be
random when I run nmap on machines running the game
with no firewall. Is there a way to
allow one or multiple machines behind the firewall to join/host a game by
forwarding the ports.
I attached my iptables script that I’m
currently using. Thanks, Matt |
#!/bin/sh # # rc.firewall - Initial SIMPLE IP Firewall script for Linux 2.4.x and iptables # # Copyright (C) 2001 Oskar Andreasson <blueflux@xxxxxxxxxxx> # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; version 2 of the License. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program or from the site that you downloaded it # from; if not, write to the Free Software Foundation, Inc., 59 Temple # Place, Suite 330, Boston, MA 02111-1307 USA # ########################################################################### # # 1. Configuration options. # ########################################################################### # # Local Area Network configuration. # # your LAN's IP range and localhost IP. /24 means to only use the first 24 # bits of the 32 bit IP adress. the same as netmask 255.255.255.0 # LAN_IP="192.168.0.254" LAN_IP_RANGE="192.168.0.0/16" LAN_BCAST_ADRESS="192.168.255.255" LAN_IFACE="eth1" ########################################################################### # w # Localhost Configuration. # LO_IFACE="lo" LO_IP="127.0.0.1" ########################################################################### # # Internet Configuration. # INET_IP="12.251.163.214" INET_IFACE="eth0" ########################################################################### # # IPTables Configuration. # IPTABLES="/sbin/iptables" ########################################################################### # # 2. Module loading. # # # Needed to initially load modules # /sbin/depmod -a # # Adds some iptables targets like LOG, REJECT and MASQUARADE. # /sbin/modprobe ip_conntrack /sbin/modprobe ip_tables /sbin/modprobe iptable_filter /sbin/modprobe iptable_mangle /sbin/modprobe iptable_nat /sbin/modprobe ipt_LOG #/sbin/modprobe ipt_REJECT #/sbin/modprobe ipt_MASQUERADE # # Support for owner matching # #/sbin/modprobe ipt_owner # # Support for connection tracking of FTP and IRC. # #/sbin/modprobe ip_conntrack_ftp #/sbin/modprobe ip_conntrack_irc ########################################################################### # # 3. /proc set up. # # Enable ip_forward if you have two or more networks, including the # Internet, that needs forwarding of packets through this box. This is # critical since it is turned off as default in Linux. # echo "1" > /proc/sys/net/ipv4/ip_forward # # Dynamic IP users: # #echo "1" > /proc/sys/net/ipv4/ip_dynaddr ########################################################################### # # 4. IPTables rules set up. # # Set default policies for the INPUT, FORWARD and OUTPUT chains. # Drop ALL packets $IPTABLES -P INPUT DROP $IPTABLES -P OUTPUT DROP $IPTABLES -P FORWARD DROP # # bad_tcp_packets chain # # Take care of bad TCP packets that we don't want. # $IPTABLES -N bad_tcp_packets $IPTABLES -A bad_tcp_packets -p tcp ! --syn -m state --state NEW -j LOG \ --log-prefix "New not syn:" $IPTABLES -A bad_tcp_packets -p tcp ! --syn -m state --state NEW -j DROP # # Do some checks for obviously spoofed IP's # $IPTABLES -A bad_tcp_packets -i $INET_IFACE -s 192.168.0.0/16 -j DROP $IPTABLES -A bad_tcp_packets -i $INET_IFACE -s 10.0.0.0/8 -j DROP $IPTABLES -A bad_tcp_packets -i $INET_IFACE -s 172.16.0.0/12 -j DROP # # Enable simple IP Forwarding and Network Address Translation # $IPTABLES -t nat -A POSTROUTING -o $INET_IFACE -j SNAT --to-source $INET_IP # # Bad TCP packets we don't want # $IPTABLES -A FORWARD -p tcp -j bad_tcp_packets # # Accept the packets we actually want to forward # $IPTABLES -A FORWARD -i $LAN_IFACE -j ACCEPT $IPTABLES -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT $IPTABLES -A FORWARD -m limit --limit 3/minute --limit-burst 3 -j LOG \ --log-level DEBUG --log-prefix "IPT FORWARD packet died: " # # Create separate chains for ICMP, TCP and UDP to traverse # $IPTABLES -N icmp_packets $IPTABLES -N tcp_packets $IPTABLES -N udpincoming_packets # # The allowed chain for TCP connections # $IPTABLES -N allowed $IPTABLES -A allowed -p TCP --syn -j ACCEPT $IPTABLES -A allowed -p TCP -m state --state ESTABLISHED,RELATED -j ACCEPT $IPTABLES -A allowed -p TCP -j DROP # # ICMP rules # # Changed rules totally $IPTABLES -A icmp_packets -p ICMP -s 0/0 --icmp-type 8 -j ACCEPT $IPTABLES -A icmp_packets -p ICMP -s 0/0 --icmp-type 11 -j ACCEPT # # TCP rules # $IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 21 -j allowed $IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 22 -j allowed $IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 25 -j allowed $IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 80 -j allowed $IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 110 -j allowed $IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 113 -j allowed $IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 1723 -j allowed # # UDP ports # # nondocumented commenting out of these rules #$IPTABLES -A udpincoming_packets -p UDP -s 0/0 --source-port 53 -j ACCEPT #$IPTABLES -A udpincoming_packets -p UDP -s 0/0 --source-port 123 -j ACCEPT $IPTABLES -A udpincoming_packets -p UDP -s 0/0 --source-port 2074 -j ACCEPT $IPTABLES -A udpincoming_packets -p UDP -s 0/0 --source-port 4000 -j ACCEPT ########################## # INPUT chain # # Bad TCP packets we don't want. # $IPTABLES -A INPUT -p tcp -j bad_tcp_packets # # Rules for incoming packets from the internet. # $IPTABLES -A INPUT -p ICMP -i $INET_IFACE -j icmp_packets $IPTABLES -A INPUT -p TCP -i $INET_IFACE -j tcp_packets $IPTABLES -A INPUT -p UDP -i $INET_IFACE -j udpincoming_packets # # VPN for incoming connections to 192.168.0.1 # $IPTABLES -t nat -A PREROUTING -i eth0 -p tcp --dport 1723 -j DNAT --to 192.168.0.1 $IPTABLES -t nat -A PREROUTING -i eth0 -p 47 -j DNAT --to 192.168.0.1 $IPTABLES -A FORWARD -p tcp -d 192.168.0.1/16 --dport 1723 -j ACCEPT $IPTABLES -A FORWARD -p 47 -d 192.168.0.1/16 -j ACCEPT # #E-Mail routes to 192.168.0.1 # $IPTABLES -t nat -A PREROUTING -i eth0 -p tcp --dport 25 -j DNAT --to 192.168.0.1 $IPTABLES -t nat -A PREROUTING -i eth0 -p tcp --dport 110 -j DNAT --to 192.168.0.1 $IPTABLES -A FORWARD -p tcp -d 192.168.0.1 --dport 25 -j ACCEPT $IPTABLES -A FORWARD -p tcp -s 192.168.0.1 --dport 25 -j ACCEPT # Rules for special networks not part of the Internet # $IPTABLES -A INPUT -p ALL -i $LAN_IFACE -d $LAN_BCAST_ADRESS -j ACCEPT $IPTABLES -A INPUT -p ALL -i $LO_IFACE -s $LO_IP -j ACCEPT $IPTABLES -A INPUT -p ALL -i $LO_IFACE -s $LAN_IP -j ACCEPT $IPTABLES -A INPUT -p ALL -i $LO_IFACE -s $INET_IP -j ACCEPT $IPTABLES -A INPUT -p ALL -i $LAN_IFACE -s $LAN_IP_RANGE -j ACCEPT $IPTABLES -A INPUT -p ALL -d $INET_IP -m state --state ESTABLISHED,RELATED \ -j ACCEPT $IPTABLES -A INPUT -m limit --limit 3/minute --limit-burst 3 -j LOG \ --log-level DEBUG --log-prefix "IPT INPUT packet died: " ############################### # OUTPUT chain # # # Bad TCP packets we don't want. # $IPTABLES -A OUTPUT -p tcp -j bad_tcp_packets # # Special OUTPUT rules to decide which IP's to allow. # $IPTABLES -A OUTPUT -p ALL -s $LO_IP -j ACCEPT $IPTABLES -A OUTPUT -p ALL -s $LAN_IP -j ACCEPT $IPTABLES -A OUTPUT -p ALL -s $INET_IP -j ACCEPT # # Log weird packets that don't match the above. # $IPTABLES -A OUTPUT -m limit --limit 3/minute --limit-burst 3 -j LOG \ --log-level DEBUG --log-prefix "IPT OUTPUT packet died: "
