sudo -E firehol panic [ IP ]
firehol command [ -- conf-arg... ]
firehol CONFIGFILE [start|debug|try] [-- conf-arg... ]
Running firehol invokes iptables(8) to manipulate your firewall.
Run without any arguments, firehol will present some help on usage.
When given CONFIGFILE, firehol will use the named file instead of /etc/firehol/firehol.conf as its configuration. If no command is given, firehol assumes try.
It is possible to pass arguments for use by the configuration file separating any conf-arg values from the rest of the arguments with --. The arguments are accessible in the configuration using standard bash(1) syntax e.g. $1, $2, etc.
To block all communication, invoke firehol with the panic command.
FireHOL removes all rules from the running firewall and then DROPs all traffic on all iptables(8) tables (mangle, nat, filter) and pre-defined chains (PREROUTING, INPUT, FORWARD, OUTPUT, POSTROUTING).
DROPing is not done by changing the default policy to DROP, but by adding one rule per table/chain to drop all traffic. This allows systems which do not reset all the chains to ACCEPT when starting to function correctly.
When activating panic mode, FireHOL checks for the existence of the SSH_CLIENT shell environment variable, which is set by ssh(1). If it finds this, then panic mode will allow the established SSH connection specified in this variable to operate.
If SSH_CLIENT is not set, the IP after the panic argument allows you to give an IP address for which all established connections between the IP address and the host in panic will be allowed to continue.
- start; restart
Activates the firewall using /etc/firehol/firehol.conf.
Use of the term restart is allowed for compatibility with common init implementations.
Activates the firewall, waiting for the user to type the word
If this word is not typed within 30 seconds, the previous firewall is
Stops a running iptables(8) firewall by clearing all of the tables and
chains and setting the default policies to ACCEPT.
This will allow all traffic to pass unchecked.
Restarts the FireHOL firewall only if it is already active.
This is the generally expected behaviour (but opposite to FireHOL prior
Shows the running firewall, using
/sbin/iptables -nxvL | less.
Start the firewall and then save it using iptables-save(8) to the
location given by FIREHOL_AUTOSAVE.
See firehol-variables(5) for more information.
The required kernel modules are saved to an executable shell script /var/spool/firehol/last_save_modules.sh, which can be called during boot if a firewall is to be restored.
External changes may cause a firewall restored after a reboot to not work as intended where starting the firewall with FireHOL will work.
This is because as part of starting a firewall, FireHOL checks some changeable values. For instance the current kernel configuration is checked (for client port ranges), and RPC servers are queried (to allow correct functioning of the NFS service).
Parses the configuration file but instead of activating it, FireHOL
shows the generated iptables(8) statements.
Enters an interactive mode where FireHOL accepts normal configuration
commands and presents the generated iptables(8) commands for each of
them, together with some reasoning for its purpose.
Additionally, FireHOL automatically generates a configuration script based on the successful commands given.
Some extra commands are available in explain mode.
Present some help
Present the generated configuration
Exit interactive mode and quit
- helpme; wizard
Tries to guess the FireHOL configuration needed for the current machine.
FireHOL will not stop or alter the running firewall. The configuration file is given in the standard output of firehol, thus firehol helpme > /tmp/firehol.conf will produce the output in /tmp/firehol.conf.
The generated FireHOL configuration must be edited before use on your systems. You are required to take a number of decisions; the comments in the generated file will instruct you in the choices you must make.
AUTHORSFireHOL Team; Original man page by Marc Brockschmidt.