SYNOPSIS
fiaif <start|stop|restart|force-reload|status|panic|tc-start|tc-stop|tc-status>
DESCRIPTION
Fiaif deploys a packet-filtering firewall by reading configuration files and setting up IP packet filtering rules using iptables. The firewall is "zone" based, meaning that each network interface is associated with a defined piece of the "IP universe" on the other side of that interface from the host. A zone is defined in a text file (the zone configuration file) listing rules for the handling of IP traffic into, out of, and through the associated interface. The rules spell out which connections to accept, which to reject, which to ignore, and which to forward through the firewall. It is also possible to setup source and destination NAT for altering the source and/or destination addresses of packets as they pass through. All non-accepted packets are logged to the system log.It should be noted that any packet related to an already accepted connection is allowed though the firewall.
OPTIONS
- start
-
This will save the current state of netfilter, and apply the new
firewall as described in the configuration files.
- stop
-
Restores the state saved when FIAIF was started.
- restart
-
Same as stop,start
- force-reload
-
This option is the same as start, although it does not use any
previously saved rules, and can be used even if fiaif has already been
started.
- panic
-
Shut off all IP traffic - don't accept any packets from anywhere for
any reason.
This can be used, for example, if uninvited guests are discovered on
the system to quickly close the firewall and start analyzing log files.
- status
-
Lists all rules in the firewall.
- test
-
Instead of deploying the firewall, all rules are written to the file
specified in the "TEST_FILE" parameter in the global configuration
file. This command also runs a sanity check on the networking
configuration. Any problems or warnings arising from this check are
printed to STDERR. Refer to
http://www.linuxhq.com/kernel/v2.4/doc/networking/ip-sysctl.txt.html
for details on settings tested. When deployed, FIAIF can automatically
fix the warnings and/or errors displayed. Please see
fiaif.conf(8) for more information.
FILES
/etc/fiaif/fiaif.conf- The global configuration file. See fiaif.conf(8) for further details.
/var/lib/fiaif/fiaif
- file containing rules generated by fiaif.
- previous netfilter state
/var/lib/fiaif/sysctl
- previous state of /proc before fiaif was started.
/var/log/messages
- All illegal packets are logged to this file though syslog(3)
DIAGNOSTICS
Errors are logged to STDOUT. If any errors is printed, then please recheck your configuration files.
ENVIRONMENT
If the NO_CLEANUP variable is set to a non-empty value, then rules are not cleaned up after FIAIF is started. This will speed up FIAIF startup time, but at the cost of having lots of rules and performance may (on small systems with many zones) be affected. On a three zone system FIAIF generated in total 310 rules. After cleaning up the rules, the number of rules was down to 241. A reduction of 22%.The FIAIF_CONF can be used to specify an anternative global configurationfile, rather than using the default /etc/fiaif/fiaif.conf. This can be used to ease switching between two different firewall configurations.
BUGS
The test command line option is no guarantee that the firewall will perform as expected, only that the syntax is correct. Only limited semantic checks of rulesis performed.