Here is the firewall script I am attempting to use/modify to work The goal is to forward some services/port back to a system on the niternal network while allowing everyone on the internal network access to the internet. # #!/bin/sh # # Insert the required kernel modules # commented modules already loaded by os #/sbin/modprobe ip_conntrack #/sbin/modprobe iptable_filter #/sbin/modprobe iptable_mangle #/sbin/modprobe iptable_nat /sbin/modprobe ip_conntrack_ftp /sbin/modprobe ip_tables /sbin/modprobe ipt_LOG /sbin/modprobe ipt_REJECT /sbin/modprobe ipt_MASQUERADE # Set default policies for packets going through this firewall box iptables -N PREROUTING iptables -N POSTROUTING iptables -t nat -P PREROUTING DROP iptables -t nat -P POSTROUTING DROP iptables -P FORWARD DROP # Set default policies for packet entering this box iptables -P OUTPUT ALLOW iptables -P INPUT ALLOW # Anything coming from our internal network should have only our addresses! iptables -A FORWARD -i eth1 -s ! $192.168.8.0/24 -j DROP # Anything coming from the Internet should have a real Internet address #iptables -A FORWARD -i eth0 -s 192.168.0.0/16 <http://192.168.0.0/16> -j DROP iptables -A FORWARD -i eth0 -s 172.16.0.0/12 <http://172.16.0.0/12> -j DROP iptables -A FORWARD -i eth0 -s 10.0.0.0/8 <http://10.0.0.0/8> -j DROP # Note:There are more "reserved" networks, but these are the classical ones. # Block outgoing network filesharing protocols that aren't designed # to leave the LAN # SMB / Windows filesharing iptables -A FORWARD -p tcp --sport 137:139 -j DROP iptables -A FORWARD -p udp --sport 137:139 -j DROP # NFS Mount Service (TCP/UDP 635) iptables -A FORWARD -p tcp --sport 635 -j DROP iptables -A FORWARD -p udp --sport 635 -j DROP # NFS (TCP/UDP 2049) iptables -A FORWARD -p tcp --sport 2049 -j DROP iptables -A FORWARD -p udp --sport 2049 -j DROP # Portmapper (TCP/UDP 111) iptables -A FORWARD -p tcp --sport 111 -j DROP iptables -A FORWARD -p udp --sport 111 -j DROP # Block incoming syslog, lpr, rsh, rexec... iptables -A FORWARD -i eth0 -p udp --dport syslog -j DROP iptables -A FORWARD -i eth0 -p tcp --dport 515 -j DROP iptables -A FORWARD -i eth0 -p tcp --dport 514 -j DROP iptables -A FORWARD -i eth0 -p tcp --dport 512 -j DROP # Transparently redirect web connections from outside to the web server iptables -t nat -A PREROUTING -i eth0 -d 192.168.8.1 <http://192.168.8.1>-dport 80 -j DNAT --to 192.168.8.96 <http://192.168.8.96> # Source NAT to get Internet traffic through # do i need to do something like this? #$INTERNET = 10.0.0.1 <http://10.0.0.1> #iptables -t nat -A POSTROUTING -o eth1 -j SNAT --to $INTERNET # Activate the forwarding! echo 1 >/proc/sys/net/ipv4/ip_forward When running this script as root (chmod 755 permisions) I get the following error: [root@gtds-vpnserver init.d]# ./masqfirewall.sh not found.le ip_conntrack_ftp not found.le ip_tables not found.le ipt_LOG not found.le ipt_REJECT not found.le ipt_MASQUERADE : command not foundline 14: iptables: Chain already exists iptables: Chain already exists iptables: Bad policy name iptables: Bad policy name iptables: Bad policy name : command not foundline 21: : command not foundline 23: iptables: Bad policy name iptables: Bad policy name : command not foundline 26: 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. : command not foundline 29: 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. : command not foundline 34: : command not foundline 36: : command not foundline 39: 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. : command not foundline 52: 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. 'ptables v1.3.0: Invalid target name `DROP Try `iptables -h' or 'iptables --help' for more information. : command not foundline 58: iptables v1.3.0: multiple -d flags not allowed Try `iptables -h' or 'iptables --help' for more information. : command not foundline 61: : command not foundline 66: : No such file or directory /proc/sys/net/ipv4/ip_forward : command not foundline 69: [root@gtds-vpnserver init.d]# These errors don't make sense as the modprobes work fine from the commandline I have tried about four ready-made firewall scripts from http://www.linuxguruz.com/iptables/ just to see if it was something weird in my script and encounter very similar problems. Has anyone had any luck with this on Fedora Core 4 or is there something I am missing? The last time I made a firewall/router was when ipchains was the thing to use so I am not entirely unfamiliar with the process. Thanks! Tim
