ISOTPSERVER(1)

💖 ISOTPSERVER(1) — the manual page for isotpserver, bestie edition 💖

okay so this is isotpserver, from the User Commands section of the manual. it's version 2023.03-1build1 and it is literally the little server that speaks ISO-TP over your CAN interface. strap in, we're doing this together 🫶

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✨ SYNOPSIS ✨

isotpserver -l <port> -s <can_id> -d <can_id> [options] <CAN interface>

that's the whole vibe: you give it a port, a source id, a destination id, and the CAN interface, and it goes to work. the rest is just ✨options✨

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🌸 OPTIONS 🌸

no cap, there are a Lot of ways to fine-tune this thing. here's every single one, organized the way the page organizes them.

🎀 ip addressing

• -l <port> — the local port for the server. this is a mandatory option bestie, you can't skip it. (also, fun fact: this is one of the only two values that are not in hex — it's a plain old port number.)

🦋 isotp addressing

• -s <can_id> — the source can_id. mandatory. if you're using extended IDs, use 8 digits for it, okay? don't be out here with 3 digits and act surprised.
• -d <can_id> — the destination can_id. also mandatory. same deal: 8 digits for extended IDs.
• -x <addr>[:<rxaddr>] — extended addressing. you can optionally pass a separate rxaddr with the colon, iykyk. 🌈
• -L <mtu>:<tx_dl>:<tx_flags> — link layer options for CAN FD. three things, colon-separated, no notes. 💅

💅 padding

• -p [tx]:[rx] — set and enable tx/rx padding bytes. note the square brackets: both parts are optional-shaped, and the colon is what separates them.
• -P <mode> — check rx padding for (l)ength, (c)ontent, or (a)ll. so your mode is one of those letters, bestie.

🍓 rx path

this is the config that gets sent to the sender / data source. yes that's literally what the page says. 👑

• -b <bs> — blocksize. 0 means off. that's it, that's the whole thing.
• -m <val> — STmin in ms/ns. see the spec for the details, because this page is not about to explain it to you. 😭
• -w <num> — max. wait frame transmissions.

🧚 tx path

and this one is the config that changes your local tx settings. two different flavors of config, don't mix them up.

• -t <time ns> — transmit time in nanosecs. (this is the other non-hex value! just -l and -t, those two, everything else is hex.)

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⭐ (* = mandatory option) — the page really does shout this at you in a footnote, so we're shouting it too: -l, -s, and -d are not optional. periodt.

💀 All values except for '-l' and '-t' are expected in hexadecimal values. — this is the trap that gets everybody. port is decimal-ish, transmit time is in ns as given, and everything else is hex. don't come crying to me when your -m value gets interpreted wrong. 🙈

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👑 SEE ALSO

nothing listed on this page itself, bestie — the SEE ALSO section is empty, so there's no cross-referencing to do here. go read the ISO-TP spec if you want the lore.

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and that's the whole page, no cap, every flag accounted for, not a single option left behind. 💖

this cutie is isotpserver version 2023.03-1build1, dated December 2025. go forth and serve those ISO-TP frames, main character. 🎀✨