tcpblast(8) tool for measuring network bandwidth


tcpblast [options] destination[:port]


tcpblast/udpblast is a simple tool for probing network and estimating its throughput. By default it sends 300 blocks (1024 bytes each) of data to specified destination host.

Destination can be name or address, IPv4 or IPv6. When IPv6 address is specified with port it should look like: `[3ffe:8010::1]:9' (with single quotes to prevent shell expansion of []).


-4, --ipv4 use only ipv4 address

-6, --ipv6 use only ipv6 address

-a send random data

-b BUF_SIZE socket buf size (default: -1, don't change), with `-' to be substracted from results

-c, --count BLOCKS change default (300) number of blocks, range: 1..10000000

-d DOTFREQ print dot every DOTFREQ blocks, disables cont. speed disp.

-h, --help this help

-i, --delay DELAY write delay in microseconds (EXPERIMENTAL)

-l, --last BLKS show also speed for last BLKS blocks

-m results for every block in separate line

-n, --nwrite do not write, use e.g. with chargen port

-o switch from continuous speed displaying to dots printing

-p PORT bind this local PORT

-q --quiet show only final statistics

-r, --read read data returned to us, switches default port to echo

-R, --rate RATESPEC limit the speed according to the RATESPEC

-s BLOCK_SIZE block size (default 1024 bytes)

-t MAXTIME limit time to MAXTIME (up to 42950 h)

--tcp use TCP (default)

--udp use UDP (default if named udpblast)

-v, --verbosity verbosity, default 0, maximum 3. -v adds time display, -vv also speed in B/s, -v - speed in b/s.

-V, --version version

destination host name or address

port use port #/name xyz instead of default port 9

RATESPEC RATE[,TIME][:RATE[,TIME]]... RATE generating data at RATE speed in B/s TIME for TIME seconds (can be floating point number), last can
                   be omitted and that time will be infinite

Options -b, -c, -R, -s and -t can use case insensitive unit multipliers and specifiers:
  size (bytes):
    -b and -s argument without units is in bytes, can use [{k,m,g}]b (lower
    or upper case) for KBMB or GB. {k,m,g} are powers of 1024.
    -c argument is just a number, can have k, m or g added (powers of 1024),
    no unit needed
  rate (bytes pes second):
    -R RATE is in B/s or Bps, the postfixes can be [{k,m,g}]{b/s,bps}
  time (seconds):
    -t and -R TIME argument is in seconds, can be postfixed with

  tcpblast -b 4KB -c 10k -R 10kbps,2:20kbps,3s target

tcpblast version: FreeBSD + rzm 20001030


Rafal says that he is a perfectly bad and careless maintainer :)

If You found any other bugs send it to him.


Software: [email protected] (Daniel Karrenberg - acc. to FreeBSD version)

Maintained by: Rafal Maszkowski <[email protected]>

Manual page: Artur R. Czechowski <[email protected]>, Oct 1999; rzm, Oct 2000