firehol-mac(5)

📦
version 3.1.8 · 4 versions
, in debian trixie, ubuntu resolute, ubuntu stonking

💅 firehol-mac — bestie edition ✨

okay so this is the firehol-mac(5) page from the FireHOL manual, version 3.1.8, and it's literally just one tiny command that does one very specific, very iconic job 🎀

✨ NAME ✨

firehol-mac — make sure the source IP and the source MAC address actually match, no cap 🫶

🌸 SYNOPSIS 🌸

mac IP macaddr

💖 DESCRIPTION 💖

so here's the vibe: any mac command you write is gonna affect all the traffic headed for the firewall host itself, or traffic that's gonna be forwarded by the host. all of it. the whole thing. 👑

and the placement matters, bestie — you gotta declare these before the first router or interface. don't be out here putting them after, that's not the move 🙈

📌 Note: there's ALSO a mac parameter that lets you match MAC addresses inside individual rules — go peek at firehol-params(5) for that one, it's a whole different girl 💅

The mac helper command DROPs traffic coming from that IP address if it wasn't sent using the macaddr you specified. like, sorry babe, wrong MAC, we're not doing this today 💀

When packets get dropped, a log pops out with the label “MAC MISSMATCH” — yes, that's spelled like that, (sic.), the original really said that and we're respecting it fr fr 😭

And mac plays by the default log limits, so check out the [LOGGING] section in firehol-params(5) if you wanna know the rules of the game.

📌 Note: this command pins one IP to one particular MAC address. BUT — and this is important — the same MAC address is still allowed to send traffic using a different IP. it's one-way restriction energy, not a full lockdown, iykyk 🌈

🦋 EXAMPLES 🦋

mac 192.0.2.1    00:01:01:00:00:e6
mac 198.51.100.1 00:01:01:02:aa:e8

⭐ SEE ALSO ⭐

  • firehol(1) — the FireHOL program itself 👑
  • firehol.conf(5) — your FireHOL configuration 🎀
  • firehol-params(5) — the optional rule parameters 🌸
  • FireHOL Website 🌐
  • FireHOL Online PDF Manual 📄
  • FireHOL Online Documentation 📚

💜 AUTHORS 💜

FireHOL Team. (shoutout to the squad, they ate and left no crumbs 🫶)

and that's the whole page, bestie!! this was built by the FireHOL Reference on 13 Apr 2025 (that's the FireHOL 3.1.8 era, for the record), so if you're reading this later just know the lore is from that moment in time ✨ mwah, go forth and match those MACs 💅💖

📦 where this page comes from