5.1. Loading up the rc.firewall ruleset

Ok, run the command "/etc/rc.d/rc.firewall".

Does it load without any strange errors? Yes, try these tests:

• ip_tables, Using /lib/modules/2.4.2-2/kernel/net/ipv4/netfilter/ip_tables.o /lib/modules/2.4.2-2/kernel/net/ipv4/netfilter/ip_tables.o: init_module: Device or resource busy Hint: insmod errors can be caused by incorrect module parameters, including invalid IO or IRQ parameters

  Run the command "/sbin/lsmod" and make sure the module "ipchains.o" is NOT installed. If it is installed, your machine (most likely Redhat-7.x based) is probably trying to load an IPCHAINS ruleset which is incompatible with IPTABLES.

  To disable this from happening in the future, run the command:

  chkconfig --level=2345 ipchains off

  To remove the "ipchains" module without rebooting, run the command:

  /sbin/rmmod ipchains

  and the re-try to load the rc.firewall ruleset.

• No such file: Did you copy this rc.firewall file from a DOS machine? Load the rc.firewall file in a binary editor (vim -b /etc/rc.d/rc.firewall) and make sure that every line is NOT finished with a ^M.