PPP(4)

💅 PPP(4) — like, the whole point-to-point situation

okay bestie, welcome to the ppp page from the Kernel Interfaces Manual — yes it's a section 4, yes it's a kernel thing, no you don't have to be scared 🫶

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✨ NAME ✨

ppp — the point to point protocol network interface, aka the moment your serial line decides it wants main character energy and becomes a whole network interface 💅

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✨ SYNOPSIS ✨

Like all the good kernel-config stuff, it's giving "you gotta declare it first":

options PPP_BSDCOMP
options PPP_DEFLATE
options PPP_FILTER

pseudo-device ppp

periodt. that's the whole vibe check 💖

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✨ DESCRIPTION ✨

so here's the tea: the ppp interface lets you use serial lines as network interfaces using the Point-to-Point Protocol (PPP). literally turning a cable into a network. iconic behavior 🎀

and it's not just basic either — the ppp interface can use various types of compression and has like so many features over the SLIP protocol used by the sl(4) interface. sl could never, ngl 😭

The supported options are, and yes you need to know all of them:

• options PPP_BSDCOMP — turns on support for BSD-compress (bsdcomp) compression in ppp. compression slay 💅
• options PPP_DEFLATE — turns on support for deflate compression in ppp. the other compression, also slay ✨
• options PPP_FILTER — this one turns on pcap(3) based filtering for ppp connections 🦋. This option is used by pppd(8) which needs to be compiled with PPP_FILTER defined (the current default). so like, it's already the default, but now you know why 👑

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✨ DIAGNOSTICS ✨

sometimes the kernel is dramatic and says:

ppp%d: af%d not supported .

(no I didn't add that space before the period, that's literally how it's written, don't come for me 💀)

what it means: the interface was handed a message with addresses formatted in an unsuitable address family, and the packet was dropped. rip packet, we hardly knew ye 🙈

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✨ SEE ALSO ✨

the whole friend group:

• inet(4)
• intro(4)
• sl(4)
• pppd(8)
• pppstats(8)

and the absolute celebrity reference:

• The Point-to-Point Protocol (PPP), RFC 1661, July 1994. the original icon, respect the elders 👑

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✨ HISTORY ✨

the ppp device appeared in NetBSD 1.0. vintage. antique. still serving 💜

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✨ BUGS ✨

⚠️ Currently, only the ip(4) and ip6(4) protocols are supported.

that's it, that's the bug list. no cap, only ip and ip6 get to sit at the cool table 🍓

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🌸 okay that's the whole page, you're officially a ppp girlie now 💅

huge kiss goodbye from the Debian crew, dated January 10, 2005 — yeah, old page, but the info still hits 🌈✨