NAME

trpt — transliterate protocol trace

SYNOPSIS

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

DESCRIPTION

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 question.

SYSCTLS

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.

DIAGNOSTICS

no namelist

When the image doesn't contain the proper symbols to find the trace buffer; others which should be self explanatory.

SEE ALSO

netstat(1), setsockopt(2)

HISTORY

The trpt command appeared in 4.2BSD.

BUGS

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.