NAME

tcpstat.d - print TCP statistics. Uses DTrace.

SYNOPSIS

tcpstat.d

DESCRIPTION

tcpstat.d is a DTrace program to print TCP statistics every second, retrieved from the MIB provider.

This program can be used to help identify how utilised the network interfaces may be, as well as TCP transmission errors.

The TCP statistics are documented in the mib2_tcp struct in /usr/include/inet/mib2.h; and also in the mib provider chapter of the DTrace Guide, found at http://docs.sun.com/db/doc/817-6223.

Since this uses DTrace, only the root user or users with the dtrace_kernel privilege can run this command.

OS

Solaris

STABILITY

stable - needs the mib provider.

EXAMPLES

Print statistics every second,

# tcpstat.d

FIELDS

TCP_out

TCP bytes sent

TCP_outRe

TCP bytes retransmitted

TCP_in

TCP bytes received

TCP_inDup

TCP bytes received duplicated

TCP_inUn

TCP bytes received out of order

DOCUMENTATION

See the DTraceToolkit for further documentation under the Docs directory. The DTraceToolkit docs may include full worked examples with verbose descriptions explaining the output.

EXIT

tcpstat.d will run forever until Ctrl-C is hit.

AUTHOR

Brendan Gregg [Sydney, Australia]

SEE ALSO

nicstat(1M), dtrace(1M)