“There’s an RFC for that.”

That’s something my colleague and resident networking genius, Jefferson Cowart, says right before my brain prepares for impact.

We were in the middle of a migration from static routing to dynamic (BGP) when Jefferson casually dropped,

“You should probably be aware of the evil bit.”

Now, I didn’t say it out loud (because I didn’t want to sound stupid), but my first thought was:

“What the heck is the evil bit?”

As usual, Jefferson had an RFC ready — RFC 3514: “The Security Flag in the IPv4 Header” — also known as the evil bit.

For context, this is a 2003 IETF April Fool’s RFC that defines a “security flag” in IPv4 packets.

Here’s the gist:

If the evil bit = 0, the packet has no evil intent.
If the evil bit = 1, the packet has evil intent, and secure systems should defend themselves accordingly.

Problem solved, right? If only malware authors were this honest.

Jefferson went on to explain (somewhere between BGP sessions and Palo Alto configs) how “firewalls and IDS would love if that bit were real.”

I nodded thoughtfully… and maybe zoned out somewhere between “autonomous systems” and “Border Gateway Protocol.”

Later, I replayed the session and caught the gem:

“Firewalls, or in our case the Palo Alto Networks PANs, need a way to distinguish between good and bad actors. So, they created the ‘evil bit,’ which gets stripped out of the IPv4 header in AS, but would remain in a malicious payload from an attacker.”

Of course, it’s a joke RFC — but it’s also a clever reminder:
Security would be easy if bad actors self-identified.

Until then, we’ll keep doing it the hard way.

Live long and route prosper. 🖖

#Networking #BGP #IPv4 #Cybersecurity #PaloAltoNetworks #RFC3514 #TechHumor