NAME

       axlisten - monitor AX.25 traffic

SYNOPSIS

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

DESCRIPTION

       Axlisten  uses  SOCK_PACKET  facilities  to provide a network monitor of all AX.25 traffic
       heard by the system. Since KISS is implicitly promiscuous no special driver configurations
       are needed.

       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.  The  program  also displays AX.25 and IP encapsulated within an IP frame, but see
       RFC1326 for reasons not to do so.

       Axlisten makes an attempt at decoding some of the more common routing protocols. RSPF  and
       RIP  (both  “normal”  and G8BPQs RIP98) are traced. JNOS style NET/ROM node polls are also
       displayed.

       Axlisten can use colors to make the output more readable. The ncurses library is  used  to
       accomplish  this.   Color support defaults to being disabled, and the -c parameter is used
       to enable it.

OPTIONS

       -8        Indicates that the terminal  is  capable  of  printing  8-bit  characters.  This
                 parameter is required for the -i parameter to work.

       -a        Allow for the monitoring of outgoing frames as well as incoming ones.

       -c        Enable color support.

       -h        Dump  the  data portion of the packet in both hexadecimal and ASCII. The default
                 is to display data as ASCII only.

       -i        Map IBM codepage 437 characters 128-158 to their ISO-Latin-1 equivalents.   This
                 is  a  hack  for scandinavian users. This parameter is only valid when used with
                 the -8 and -c parameters.

       -p port   Monitor only those frames received on a particular port, by  default  all  AX.25
                 devices are monitored.

       -r        Dump  the  data  portion  in  a  "readable"  fashion, which is more suitable for
                 tracing plaintext AX.25 traffic. CR-LF conversion is done.

       -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 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 current and first line on
                 each dump line.

       -v        Display the version.

FILES

       /etc/ax25/axports

SEE ALSO

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

BUGS

       Axlisten does not validate the checksums of frames that support them  (ie  IP),  therefore
       corrupt  frames  will be displayed with bogus values. The MSS of a TCP frame that contains
       that option is not displayed.

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>