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Questions tagged [iperf]

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30 views

Iperf giving wrong results

I ran TCP throughput from client(iperf -c IP -i1 -p19223) to server(iperf -s -i1 -p19223). The stats showed me bandwidth of ~5Gbps. However, when I ran iptraf on the server, I came to know that ...
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0answers
182 views

TCP traffic not working through Iperf tool in ubuntu

I am using system-A(interace name:tun0; IP: 192.168.3.1) and system-B(interface n ame:ss200; 192.168.3.2) which run on ubuntu. When I try sending traffic in TCP mode from A to B or vice versa, by ...
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25 views

Inconstant Bandwidth despite Bandwidth Limitation in VirtualBox

In VirtualBox, I have two Ubuntu 18.04 VMs running on an Ubuntu 18.04 host. My target is to simulate network traffic between the two VMs (one as a Server, one as a Client). Therefore I set the VM ...
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1answer
45 views

iperf: connecting to remote server consistently faster than local network

So I turned my old laptop into a home server. Both the server (old laptop) and my main machine are connected to the same router wirelessly. Both are running Ubuntu 18.04. Everything seemed to work ...
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0answers
24 views

What is the cause of these apparent discrepancies between iperf and Ookla?

I was looking at Notebookcheck's tests of laptop and smartphone speed. They used iperf, showing (for instance) that the iPhone X could receive at over 900 Mbps. This, curiously, is much higher than ...
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2answers
385 views

How can I output iperf results for only Interval and Bandwidth?

I am trying to get the output from the command iperf -c 10.0.0.1 -t 3600 -i 2 And only need the Interval and bandwidth fields listed for the entire hour of logging. I haven't used grep or awk in ...
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1answer
1k views

Understand iperf3 results

I'm trying to diagnose network performance in my house. I ran iperf3 on two Macs wired to a gigabit Ethernet switch (through cable runs in wall). My results were: Connecting to host 10.0.1.192, ...
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1answer
875 views

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 ...
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1answer
388 views

USB 3.0 Ethernet adapter outperforms motherboard PCIe GBE

I recently did three different Iperf bandwidth tests using various network adapters. My question is: How does a USB 3.0 ethernet adapter outperform a built in gigabit ethernet controller on the ...
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1answer
294 views

What means 's' and 'u' letters on CPU utilization in iperf3 command with -V?

i have very simple question: When Im using Iperf3 with my server and on client i add paramater -V which mean it will display more detailed information it's display information about CPU utilization on ...
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0answers
50 views

Achieving maximum throughput

I have these devices set up at home: DIY NAS running Debian that has ASUS PCE-AC68 NIC TP-Link AC750 Archer MR200 router MacBook Pro 2015 Some other Wi-Fi capable devices My goal is to achieve the ...
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0answers
273 views

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 ...
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1answer
608 views

TCP throughput much better than UDP

I'm monitoring the performances of a WAN link with iperf between two windows machines on both ends. Surprisingly (for me), TCP single session default window reaches a throughput of 12Mbps, while UDP ...
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3answers
4k views

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 ...
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1answer
2k views

Why does a Bidirectional iperf request freezes on the server to client side?

To diagnose the difference in network trafic between two locations and our main server center, I'm using iperf to log the traffic rate with the following command: iperf -c <server ip> -F ...
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1answer
311 views

Why does `iperf` report huge values for bandwidth?

When I try to run iperf on local server it reports reasonable values iperf -c 127.0.0.1 -p 631 ------------------------------------------------------------ Client connecting to 127.0.0.1, TCP port ...
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0answers
784 views

Speed over VPN is 10x slower than connection to VPN or VPN<=>Destination

I'm trying to setup VPN for my own use. I have noticed very strange issue with speeds which I struggle to understand. Question: What is causing slow download speed from AWSFrankfurt when using VPN? ...
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0answers
629 views

not getting fast 802.11ac WiFi speeds

I'm using a Linksys WRT AC1900 router and an Intel 7260 client adapter on my desktop. I've never seen speeds > 10MiB/s at my previous apartment, probably because the router was 30 feet away and the ...
3
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2answers
7k views

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> ...
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1answer
688 views

iperf and Wireshark show different data rate

I was testing the capture performance of a sniffer application in Linux. I have a Windows machine that sends UDP multicast packets to the capture port of the sniffer system using iperf at 8Mbits/s. I ...
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0answers
861 views

Why is iPerf UDP bandwidth so much lower that iPerf TCP?

I need to perform a single direction iPerf test. Bi-directionally, using TCP, I get 25Mbps. But single direction using UDP I only get 0.7Mbps. Why is UDP rate so much lower that TCP? iPerf client ...
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1answer
1k views

Graphical representation of iperf3 results

I'm using Iperf3 on 2 machines and actually I'm running 2 instances of Iperf3, one to generate traffic with high priority and the other generates traffic with low priority. I would like to generate a ...
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0answers
476 views

Can I have server and client on the same machine and run network bandwidth test using iperf?

I have two ethernet ports (eth0 and eth1) on my system. I've tested the bandwidth with two systems and got ~940Mbit/s. If I use one of the ports as server and the other as client, I always go through ...
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1answer
5k views

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 <ip address>, it returns: bind failed: ...
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2answers
287 views

Iperf network benchmark measures under-utilized?

I am working on two embeddded high performance network routers and I have connected them point-to-point via a 10Gbit optical fibre cable. I ran iperf benchmarks on them and when I connect through an ...
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1answer
366 views

Slow LAN connection (especially receiving) on Windows 8

I was diagnosing my SMB performance issues when I noticed my whole network speed was off. These are my benchmarking results between my desktop and my Linux server: Both are connected using CAT6 and ...
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0answers
3k views

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 ...
2
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1answer
4k views

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 ...
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2answers
7k views

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 ...