DK-Software speedtest

This speedtest server is located at the DK-Software datacenters and is running on a 10GE connection with 5GB cap.

Test with IPERF

Iperf software and manuals you can find on official home page https://iperf.fr
You can find TCP Throughput calculator here.
For a more correct test, use the command like:

iperf -c speedtest.dksoft.online -P 10    (for IPv4)
iperf -c speedtest.dksoft.online -V -P 10 (for IPv6)

Also you can use IPERFv3 (client sends, server receives)

iperf3 -c speedtest.dksoft.online -p 5002 -P 10 -4    (for IPv4)
iperf3 -c speedtest.dksoft.online -p 5002 -P 10 -6    (for IPv6)

( -R reverse mode (server sends, client receives)

iperf3 -c speedtest.dksoft.online -p 5002 -P 10 -4 -R  (for IPv4)
iperf3 -c speedtest.dksoft.online -p 5002 -P 10 -6 -R  (for IPv6)

Test with download files from FTP or HTTP

This archive is available over http and ftp on both IPv4 and IPv6.

10mb.bin, 100mb.bin, 1000mb.bin, 2000mb.bin, 5000mb.bin, 10000mb.bin
For a more correct test, use the command like:

wget -4 -O /dev/null http://speedtest.dk-software.org/speedtest/files/100mb.bin (for IPv4)
wget -6 -O /dev/null http://speedtest.dk-software.org/speedtest/files/100mb.bin (for IPv6)