AXLISTEN(1)

💖 axlisten — monitor AX.25 traffic 💖

okay bestie, this is axlisten, a page from the Linux Programmer's Manual (section 1, the commands section, you know the vibes). it's giving network-monitor main character energy and i'm obsessed 💅

✨ NAME ✨

axlisten — monitor AX.25 traffic 👀

🌸 SYNOPSIS 🌸

axlisten [-8] [-a] [-c] [-h] [-i] [-p port] [-r] [-t..] [-v]

🦋 DESCRIPTION 🦋

so axlisten uses SOCK_PACKET facilities to be like, a full-on network monitor of all the AX.25 traffic heard by the system. and here's the slay part: since KISS is implicitly promiscuous, you don't need any special driver configurations. none. zero. nothing. periodt ✨

this version displays standard AX.25, PE1CHL extended AX.25, NET/ROM, Rose, ARP, IP, ICMP, TCP and UDP. it also displays IP, TCP, ICMP, TCP and UDP encapsulated within NET/ROM frames. and it also displays AX.25 and IP encapsulated within an IP frame — but bestie, go read RFC1326 for the reasons not to do that 🙈

axlisten also makes an attempt at decoding some of the more common routing protocols. RSPF and RIP (both the "normal" one and G8BPQ's RIP98) are traced. JNOS style NET/ROM node polls are displayed too. like, it really said "i'll trace everything" 👑

and axlisten can use colors to make the output more readable — the ncurses library is what makes that happen. color support defaults to being disabled, and the -c parameter is what turns it on. so if you want the pretty, you gotta ask for the pretty 💖

💜 OPTIONS 💜

• -8 — says that your terminal is capable of printing 8-bit characters. and heads up: this one is required for the -i parameter to work. no -8, no -i, that's the rule 🎀
• -a — allows for the monitoring of outgoing frames as well as incoming ones. so you get both sides of the conversation, nosy (affectionate) 🫶
• -c — enable color support. the glow-up option ✨
• -h — dumps the data portion of the packet in both hexadecimal and ASCII. the default is to display data as ASCII only.
• -i — maps IBM codepage 437 characters 128-158 to their ISO-Latin-1 equivalents. it's a hack for scandinavian users, and it is only valid when used with the -8 and -c parameters. so it's a trio or nothing, bestie 💀
• -p port — monitor only those frames received on a particular port. by default, all AX.25 devices are monitored. pick your fave 💅
• -r — dumps the data portion in a "readable" fashion, which is more suitable for tracing plaintext AX.25 traffic. CR-LF conversion is done. cozy reading mode 🌸
• -t — don't print a timestamp on each dump line.
• -tt — print an unformatted timestamp on each dump line.
• -ttt — print a delta (micro-second resolution) between the current and previous line on each dump line.
• -tttt — print a timestamp in default format proceeded by date on each dump line.
• -ttttt — print a delta (micro-second resolution) between the current and first line on each dump line.
• -v — display the version. say hi to the version number 👋

the way that -t just keeps stacking... -t through -ttttt, one more t each time, it's giving commitment 😭

🎀 FILES 🎀

/etc/ax25/axports

🌈 SEE ALSO 🌈

axcall(1), mheard(1), beacon(1), ax25(4), netrom(4), rose(4), kissattach(8).

go read those too, i believe in you 🫶

💀 BUGS 💀

okay so, real talk:

• Axlisten does not validate the checksums of frames that support them (ie IP), therefore corrupt frames will be displayed with bogus values. so if the numbers look unhinged, that's why 😭
• The MSS of a TCP frame that contains that option is not displayed. it's just... not there. gone. not shown. periodt.

👑 AUTHORS 👑

• Alan Cox GW4PTS <alan@cymru.net>
• Jonathan Naylor G4KLX <g4klx@g4klx.demon.co.uk>
• Phil Karn KA9Q <karn@qualcomm.com>
• Heikki Hannikainen OH7LZB <oh7lzb@sral.fi>
• Scott Miller N1VG <scott@opentrac.org>

legends, every single one of them 💖

and that's the page bestie! this one comes from Linux, dated 27 August 1996, and it lives in the manual as AXLISTEN(1). yes, 1996, and it's still out here monitoring AX.25 traffic like the icon it is ⭐ slay, go trace some packets 💅✨