transliterate protocol trace
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,
all the trace records found in the system grouped according to TCP
connection protocol control block (PCB).
The options are as follows:
- In addition to the normal output, print the values of the source and destination addresses for each packet recorded.
- Follow the trace as it occurs, waiting a short time for additional records each time the end of the log is reached.
- Just give a list of the protocol control block addresses for which there are trace records.
- Extract values associated with the name list from core instead of the running kernel.
- Extract the name list from system instead of the running kernel.
- Show only trace records associated with the protocol control block at the given address hex-address.
- In addition to the normal output, print a detailed description of the packet sequencing information.
- In addition to the normal output, print the values for all timers at each point in the trace.
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
trpt requires the ability to open
/dev/kmem which may be restricted based upon the
value of the kern.allowkmem
- no namelist
- When the system image doesn't contain the proper symbols to find the trace buffer; others which should be self explanatory.
trpt command appeared in
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.