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Questions tagged [iperf]

iperf is a tool for network performance measurement and tuning.

48 questions
6
votes
1 answer

Iperf for Windows - where to find newer versions?

I have just noticed that in openSuse I have iperf version 3.5, where as on Windows I cannot find anything newer then 3.1.3, which dates from June 2016! I still assume that iperf is the most recommended, cross platform, tool to measure network…
Espinosa
  • 407
4
votes
2 answers

How to perform a network loopback test using TTCP or IPERF?

The PC has two Gigabit Ethernet ports. They function as two separate network adapters. I'm trying to do a simple loopback test between the two. I've tried TTCP and IPERF. They're giving me hard time because I'm using the same physical PC. Using…
Samir
  • 21,235
4
votes
3 answers

ping works but iperf3 doesn't show any traffic for TCP

machine A has IP (eth0: 192.168.1.1, eth1: 10.10.xxx.yy) machine B has IP (eth0: 192.168.1.2) A and B are connected through RJ5 on eth0, both sides. ping works fine on both side, but when running iperf3 on a client-server mode, it doesn't show any…
iamauser
  • 175
3
votes
2 answers

iperf giving incorrect results

I've just had new broadband installed, and wanted to test its throughput using iperf3. However it appears to be giving considerably different results than more conventional speed tests. E:\tmp> iperf3 -c 3.testdebit.info - - - - - - - - - - - - - -…
Michael B
  • 784
3
votes
1 answer

iperf returning “bind failed: cannot assign requested address” in Windows XP and 7

I am trying to set up iperf on an old HP server running Windows XP Professional to test multicast, but whenever I issue the command iperf -s -u -B , it returns: bind failed: Cannot assign requested address It doesn't matter what I put…
Liesmith
  • 197
3
votes
0 answers

Iperf tests in reverse direction

I used iperf to measure the max throughput for TCP connection between two ubuntu machines. Both the machines were directly connected be means of a 1Gbps cable. When I performed iperf tests i obtained a bandwidth of 845 Mbps on an average. But when i…
user3226732
  • 141
3
votes
0 answers

Windows iperf3 speed test slower than Linux

Hardware setup NAS: Core i3 7100, Intel X540T2 10GbE Switch: Mikrotik CRS305 PC: Ryzen 7 2700, Intel X540T2 10GbE Cables: 2x Cat 7 cables Software Setup NAS: Ubuntu 20.04 alexwang@alex-nas2 ~ (master)> iperf3 --version iperf 3.7 (cJSON…
Alex Wang
  • 131
3
votes
1 answer

iperf3 error exactly 7 seconds into running the test

I am running an iperf test to measure bandwidth from a host iperf client to a container iperf server.Exactly 7 seconds into the test iperf gives an error & abruptly ends the test. The message says " iperf3: error - received an unknown control…
sum1
  • 43
2
votes
3 answers

How to run IPERF on DD-WRT?

I have IPERF for Windows installed on a desktop computer. Now I want to connect this computer to the router and conduct a simple throughput performance test. For that I will need IPERF running on the router. The router has the Linux based DD-WRT…
Samir
  • 21,235
2
votes
1 answer

Mapping network topography with nmap

I would like to create a map of my network. Currently the layout Internet | router pc | | server - switch - wap/switch - router - server | pc - wap/switch - pc I guess I…
JoSSte
  • 495
2
votes
0 answers

firewalld Zone "trusted" Drops about 15% of Frames that are Passed by Zone "public"

Background I have two lab machines, which I'll refer to as A and B, running RHEL 8.0. I SSH into A and B from my Windows desktop over a 1 GbE link, whose network interface I'll refer to as eth0. A and B also have a direct 10 GbE fiber link between…
Dave
  • 1,129
2
votes
1 answer

Why is iperf3 faster in one direction than the other?

I've got a Windows 10 PC with Realtek RTL8125b 2.5GbE interface and I have a Debian Linux 5.10 server with an Intel I225-LM (rev 3) 2.5GbE interface. Running iperf3 -s on the server I get 1.14Gbit/s. If I use -R (reverse) option on the client I get…
Chris_F
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2
votes
1 answer

iperf indicating 940 Mbits/sec using cat 5 cable

I have a box of old ethernet cables and was going to use iperf to determine if they were cat 5 or cat 5e. As a sanity check I found one that still had labels on it indicating it was cat 5 but when I connected it between 2 PCs and tested it with…
Pathead
  • 123
2
votes
1 answer

What does 's' and 'u' mean on CPU utilization in iperf3 command with -V?

When I'm using Iperf3 with my server and on client, I add paramater -V, which means it will display more detailed information it's display information about CPU utilization on server and client. Example of displayed information: CPU Utilization:…
Jacob
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2
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0 answers

iperf3 limiting bandwidth fails

I want to use iperf3 to test some QoS settings of a router. Therefore I want to simulate a lone-lasting but low bandwidth connection.* I tried the following: $ iperf3 -c MYSERVER -b 100K Connecting to host MYSERVER, port 5201 [ 4] local…
masgo
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