fwb_ipt(1)

💖 fwb_ipt — bestie's guide to the iptables policy compiler 💖

okay so you found the fwb_ipt(1) page, part of the Firewall Builder manual family, and honestly? slay. let's get into it 🎀

✨ NAME ✨

fwb_ipt — the policy compiler for iptables 🦋

✨ SYNOPSIS ✨

fwb_ipt -fdata_file.xml [-4] [-6] [-V] [-dwdir] [-i] [-ooutput.fw]
[-Ofw1_id,fw1_output.fw[,fw2_id,fw2_output.fw]] [-v] [-xc] [-xnN] [-xpN]
[-xt] object_name

✨ DESCRIPTION ✨

so fwb_ipt is a firewall policy compiler component of Firewall Builder (peep fwbuilder(1) for the whole thing, iykyk). what it does is read all the object definitions and the firewall description out of the data file you hand it with the -f option, and then it generates the resulting iptables script. 💅

that script gets written to a file whose name is literally the same as the name of the firewall object, plus the extension .fw. iconic behavior honestly.

heads up bestie: the data file and the name of the firewall object are both non-negotiable — they have to be on the command line. everything else? optional. we love a low-maintenance queen. 👑

✨ OPTIONS ✨

• -4 — generate the iptables script for the IPv4 part of the policy only. if any rules of the firewall refer to IPv6 addresses, the compiler will just skip those rules, no drama. also: -4 and -6 are exclusive — pick one, babe. if you use neither, the compiler tries to generate both parts of the script, except the IPv6 part generation is controlled by the option "Enable IPv6 support" in the "IPv6" tab of the firewall object advanced settings dialog. and that option? off by default. 🙈
• -6 — generate the iptables script for the IPv6 part of the policy. and yeah, same deal as above: if any rules of the firewall refer to IPv6 addresses, the compiler will skip these rules. 🤷♀️
• -f FILE — specify the name of the data file to be processed. this is the one you cannot skip.
• -o output.fw — specify output file name 📝
• -O fw1_id,fw1_output.fw[,fw2_id,fw2_output.fw] — the argument here is a comma separated list of firewall object IDs paired with their corresponding output file names. this one is used by the fwbuilder GUI while compiling firewall clusters. team work makes the dream work 🫶
• -d wdir — specify working directory. the compiler creates the file with the iptables script in this directory. if this parameter is missing, then the iptables script will be placed in the current working directory. ✨
• -v — be verbose: the compiler prints diagnostic messages while it works. it's giving "let me narrate my life" and we respect it 💬
• -V — print version number and quit. short, sweet, periodt.
• -i — when this option is present, the last argument on the command line is supposed to be the firewall object ID rather than its name. 👀
• -xc — when the output file name is determined automatically (i.e. flags -o or -O are not present), the file name is composed of the cluster name and member firewall name rather than just the member firewall name. this is used mostly for testing, when the same member firewall object can be a part of different clusters with different configurations. multitasking queen 💅
• -xt — this flag makes the compiler treat all fatal errors as warnings and just keep processing rules. heads up: the generated configuration script most likely will be incorrect, but it will include the error message as a comment. this flag is used for testing and debugging. 🚨

okay bestie, real talk on -xt: fatal errors → warnings, processing continues, output probably broken. it's for testing and debugging only, not for your production firewall. do not make this your personality. 😭

• -xp N — debugging flag: this causes the compiler to print a detailed description of the policy rule number "N" as it precesses it, step by step. 🔍
• -xn N — debugging flag: this causes the compiler to print a detailed description of the NAT rule number "N" as it precesses it, step by step. 🔍

✨ URL ✨

the Firewall Builder home page is located at the following URL, go say hi:

http://www.fwbuilder.org/ 🌈

✨ BUGS ✨

please report bugs using the bug tracking system on SourceForge, they genuinely want to hear it:

http://sourceforge.net/tracker/?group_id=5314&atid=105314 🐛

✨ SEE ALSO ✨

fwbuilder(1), fwb_ipf(1), fwb_pf(1) — the whole friend group 💜

and that's the whole page, bestie!! this manual page comes to you from FWB, and it's the fwb_ipt(1) page — so go compile something iconic, stay hydrated, and remember: read the docs before you touch the firewall. mwah 💖✨