Updated: 2021/Apr/14

TRPT(8)                     System Manager's Manual                    TRPT(8)

     trpt - transliterate protocol trace

     trpt [-a] [-f] [-j] [-p hex-address] [-s] [-t] [-N system] [-M core]

     trpt interrogates the buffer of TCP trace records created when a socket
     is marked for "debugging" (see setsockopt(2)), and prints a readable
     description of these records.  When no options are supplied, trpt prints
     all the trace records found in the system grouped according to TCP
     connection protocol control block (PCB).  The following options may be
     used to alter this behavior.

     -a      In addition to the normal output, print the values of the source
             and destination addresses for each packet recorded.

     -f      Follow the trace as it occurs, waiting a short time for
             additional records each time the end of the log is reached.

     -j      Just give a list of the protocol control block addresses for
             which there are trace records.

     -p      Show only trace records associated with the protocol control
             block at the given address hex-address.

     -s      In addition to the normal output, print a detailed description of
             the packet sequencing information.

     -t      in addition to the normal output, print the values for all timers
             at each point in the trace.

     -M core
             Extract values associated with the name list from core.

     -N system
             Extract the name list from system.

     The recommended use of trpt is as follows.  Isolate the problem and
     enable debugging on the socket(s) involved in the connection.  Find the
     address of the protocol control blocks associated with the sockets using
     the -A option to netstat(1).  Then run trpt with the -p option, supplying
     the associated protocol control block addresses.  The -f option can be
     used to follow the trace log once the trace is located.  If there are
     many sockets using the debugging option, the -j option may be useful in
     checking to see if any trace records are present for the socket in

     The following sysctls are used by trpt.  The TCP_DEBUG kernel option must
     be enabled.

     net.inet.tcp.debug     Structure containing TCP sockets information used
                            by trpt.

     net.inet.tcp.debx      Number of TCP debug messages.

     no namelist
             When the image doesn't contain the proper symbols to find the
             trace buffer; others which should be self explanatory.

     netstat(1), setsockopt(2)

     The trpt command appeared in 4.2BSD.

     Should also print the data for each input or output, but this is not
     saved in the trace record.

     The output format is inscrutable and should be described here.

NetBSD 9.99                     August 30, 2007                    NetBSD 9.99