Debian 11 Bullseye
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Check Network Bandwidth
2021/09/30
 
Install Iperf to Check Network Bandwidth.
It needs 2 Hosts, Sender Host and Receiver Host.
[1] Install [iperf3] on both Hosts.
root@node01:~#
apt -y install iperf3
[2] Run the command on Receiver Host like follows.
It's possible to specify the listening port to add [-p (port number)] if you need.
If port not specified. default port [5201] is used.
root@node01:~#
iperf3 -s

-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------
[3] Check Network Bandwidth to run the command on Sender Host like follows.
The example below shows that 21.8 GBytes data are transfered and the bandwidth was 18.7 Gbits/sec.
root@node02:~#
iperf3 -c node01.srv.world

Connecting to host node01.srv.world, port 5201
[  5] local 10.0.0.52 port 41542 connected to 10.0.0.51 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  1.92 GBytes  16.5 Gbits/sec    0   1.64 MBytes
[  5]   1.00-2.00   sec  1.97 GBytes  16.9 Gbits/sec    0   2.17 MBytes
[  5]   2.00-3.00   sec  2.05 GBytes  17.6 Gbits/sec    0   2.28 MBytes
[  5]   3.00-4.00   sec  2.28 GBytes  19.6 Gbits/sec    0   2.40 MBytes
[  5]   4.00-5.00   sec  2.27 GBytes  19.5 Gbits/sec    0   2.40 MBytes
[  5]   5.00-6.00   sec  2.27 GBytes  19.5 Gbits/sec    0   2.40 MBytes
[  5]   6.00-7.00   sec  2.27 GBytes  19.5 Gbits/sec    0   2.40 MBytes
[  5]   7.00-8.00   sec  2.27 GBytes  19.5 Gbits/sec    0   2.52 MBytes
[  5]   8.00-9.00   sec  2.25 GBytes  19.3 Gbits/sec    0   2.65 MBytes
[  5]   9.00-10.00  sec  2.25 GBytes  19.3 Gbits/sec    0   2.87 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  21.8 GBytes  18.7 Gbits/sec    0             sender
[  5]   0.00-10.00  sec  21.8 GBytes  18.7 Gbits/sec                  receiver

iperf Done.
[4] There are many options to check Network Bandwidth under various cases.
root@node02:~#
iperf3 --help

Usage: iperf3 [-s|-c host] [options]
       iperf3 [-h|--help] [-v|--version]

Server or Client:
  -p, --port      #         server port to listen on/connect to
  -f, --format   [kmgtKMGT] format to report: Kbits, Mbits, Gbits, Tbits
  -i, --interval  #         seconds between periodic throughput reports
  -F, --file name           xmit/recv the specified file
  -A, --affinity n/n,m      set CPU affinity
  -B, --bind      <host>    bind to the interface associated with the address <host>
  -V, --verbose             more detailed output
  -J, --json                output in JSON format
  --logfile f               send output to a log file
  --forceflush              force flushing output at every interval
  -d, --debug               emit debugging output
  -v, --version             show version information and quit
  -h, --help                show this message and quit
Server specific:
  -s, --server              run in server mode
  -D, --daemon              run the server as a daemon
  -I, --pidfile file        write PID file
  -1, --one-off             handle one client connection then exit
  --rsa-private-key-path    path to the RSA private key used to decrypt
                            authentication credentials
  --authorized-users-path   path to the configuration file containing user
                            credentials
Client specific:
  -c, --client    <host>    run in client mode, connecting to <host>
  --sctp                    use SCTP rather than TCP
  -X, --xbind <name>        bind SCTP association to links
  --nstreams      #         number of SCTP streams
  -u, --udp                 use UDP rather than TCP
  --connect-timeout #       timeout for control connection setup (ms)
  -b, --bitrate #[KMG][/#]  target bitrate in bits/sec (0 for unlimited)
                            (default 1 Mbit/sec for UDP, unlimited for TCP)
                            (optional slash and packet count for burst mode)
  --pacing-timer #[KMG]     set the timing for pacing, in microseconds (default 1000)
  --fq-rate #[KMG]          enable fair-queuing based socket pacing in
                            bits/sec (Linux only)
  -t, --time      #         time in seconds to transmit for (default 10 secs)
  -n, --bytes     #[KMG]    number of bytes to transmit (instead of -t)
  -k, --blockcount #[KMG]   number of blocks (packets) to transmit (instead of -t or -n)
  -l, --length    #[KMG]    length of buffer to read or write
                            (default 128 KB for TCP, dynamic or 1460 for UDP)
  --cport         <port>    bind to a specific client port (TCP and UDP, default: ephemeral port)
  -P, --parallel  #         number of parallel client streams to run
  -R, --reverse             run in reverse mode (server sends, client receives)
  -w, --window    #[KMG]    set window size / socket buffer size
  -C, --congestion <algo>   set TCP congestion control algorithm (Linux and FreeBSD only)
  -M, --set-mss   #         set TCP/SCTP maximum segment size (MTU - 40 bytes)
  -N, --no-delay            set TCP/SCTP no delay, disabling Nagle's Algorithm
  -4, --version4            only use IPv4
  -6, --version6            only use IPv6
  -S, --tos N               set the IP type of service, 0-255.
                            The usual prefixes for octal and hex can be used,
                            i.e. 52, 064 and 0x34 all specify the same value.
  --dscp N or --dscp val    set the IP dscp value, either 0-63 or symbolic.
                            Numeric values can be specified in decimal,
                            octal and hex (see --tos above).
  -L, --flowlabel N         set the IPv6 flow label (only supported on Linux)
  -Z, --zerocopy            use a 'zero copy' method of sending data
  -O, --omit N              omit the first n seconds
  -T, --title str           prefix every output line with this string
  --get-server-output       get results from server
  --udp-counters-64bit      use 64-bit counters in UDP test packets
  --username                username for authentication
  --rsa-public-key-path     path to the RSA public key used to encrypt
                            authentication credentials

[KMG] indicates options that support a K/M/G suffix for kilo-, mega-, or giga-

iperf3 homepage at: http://software.es.net/iperf/
Report bugs to:     https://github.com/esnet/iperf
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