Questions tagged [iperf]
The iperf tag has no usage guidance.
129
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iperf3: Multiple user Streams test does not start
Im trying to use iperf3 to test where issues lie at a client that uses RDP to connect to our terminal-server. Their issue is that the RDP window freezes (mouse clicks mostly still go trough). ...
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0
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34
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MPLS Implementation OpenFlow Iperf Testing
I have a mininet topology that consists of two hosts and two ovs switches. h1-eth0 is connected to s1-eth1 and h2-eth0 is connected to s2-eth2 and s1-eth2 and s2-eth1 is also connected. h1 is for ...
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51
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iPerf3 --reverse different results (2.5GB link)
I recently purchased 2.5GB adapters for my main Desktop (Windows 10) and NAS server (Ubuntu 20.04).
When testing with iPerf3 FROM Windows, I only get 1GB. But when I use the --reverse flag, I get the ...
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28
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Iperf3 on local area network: tcp vs udp
I would like to check quality of a connection on a lan using a cable which is not easy to change neither I have hw tester.
The two pcs have 'standard' windows operating systems and they are not ...
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167
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Interpret Iperf3 results for bidirectional UDP Test
I am trying to make sense of the raw logs of an iperf3 UDP bidIrectional test.
Here are the iperf3 client logs:
[ ID][Role] Interval Transfer Bitrate Jitter Lost/Total ...
- 101
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43
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KVM guest low network speed
I have a KVM guest VM running RHEL 8.7 (12vCPU, 24GB RAM) and a hypervisor with 10Gb NICs.
I'm getting weird results when using iperf3 on my guest machine as a client and a TrueNAS server as a server. ...
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591
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iperf3 test bandwidth : TCP much slower than UDP
I'm trying to find out why one of my servers, used for fileserving, is sending files at a very slow rate, around 7 Mbits/sec, through nginx.
I've been using iperf3 to test transfer rate between ...
- 101
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52
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Inconsistent iperf behaviour
I am currently setting up some tests with iperf to add artificial load between two linux servers node0 and node1.
When I run it without any bandwidth specification, iperf goes for the maximum (that is ...
- 101
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553
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Getting an iperf "connect failed: connection refused" error on ubuntu when running multiple threads
I have 3 computers hooked up to a local network. I have written a python script to open a dedicated iperf server and an iperf client on separate threads. I want every computer to connect to the other ...
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371
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iperf3 errors and retransmissions on ESXi
When running iperf3 to test a 100G connection between a VMware ESXi box and a TrueNAS Core box, I'm seeing the following on the ESXi box:
The message "iperf3: getsockopt - Function not ...
- 441
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329
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How can I use an iperf output and only grep average Bandwidth?
I am here finding a way to display the average of iperf bandwidth using the script. I am not sure whats wrong with command, i dont get the output of Bandwidth displayed. I need output something like ...
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474
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iperf3: error - unable to connect to server: No buffer space available
I am testing usb to ethernet adapters by using iperf. The product I am testing has 12 ports to test, and I have 12 usb to ethernet adapters each having their default ip address.
I am using Test Stand ...
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0
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18
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Non IPERF throughput testing between two nodes with selective path
I have been working with a multinational ISP for about 10 years and have a lot of experience with network design, development and troubleshooting. I understand the intricate workings of most switching ...
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287
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how to test 10G NIC in loopback for full throughput?
I am using 10G NIC x520-DA2 (which is x8 Lane) in windows 10 Enterprise 64 Bit on DELL Optiplex 7080 Tower with Intel Core i7-10700 . X520-DA is installed on PCie slot 2 of optiplex 7080 that is PCIe ...
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381
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Windows Server 2019 high round-trip time low transfer bandwidth
I have two Windows Servers 2019 with a round-trip time of 88 ms between them. When I try to measure bandwidth with iperf3 I get only around 16 Mbits/sec in both directions with a single stream. To get ...
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Why is iperf3 data transfer slower than scp?
I have been measuring the throughput between two hosts connected via a fiber channel. The OS is CentOS 7.9.2009 and iperf3 version is 3.1.7 (RPM). One of the tests was the measurement of transfer ...
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Benchmarking AWS outbound Internet bandwidth (egress) "up to 25 Gbps"
We conducted our tests on c6gn.2xlarge AWS instances located is us-east-1 region, which are advertised in AWS documentation to have a network performance of "Up to 25 Gbps" with a baseline ...
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303
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AMD EPYC 7413 slow down to arround 400mhz when running iperf
we are trying to setup a 40gbit connection between two servers and get weird cpu behaviour when using iperf. It is also only using around 10Gbit/s of the possible 40.
Server specs:
AMD EPYC 7413
8x ...
- 71
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31
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Does Throughput calculated adds up using multiple (all active) physical adaptor
I had a network adaptor of speed 20Gbps. By stressing this adaptor using one of benchmarking tools (netperf is the tool which I used), I was able to get ~18Gbps which is well accepted.
Now, after ...
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224
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transfer file at iperf bandwidth/throughput
I need to transfer a file between 2 servers, the output of iperf is:
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[ 3] local X.X.X.X port 58986 ...
- 558
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98
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iperf3 showing packetloss between 2 directly connected servers
I have 2 Dell PowerEdge-R620 servers with following configuration
Processor: 2 X Intel(R) Xeon(R) CPU E5-2637 v2 @ 3.50GHz
RAM: 64GB
Storage: 10 SAS drives (10K RPM) with RAID 10.
NIC: QUAD Ports 2 X ...
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Asymmetry in Linux VM transfer rate
I have two Linux VMs, let's call them VM1 and VM2.
I have on VM1 an 80 Gb file.
When I try to transfer this file from VM1 to VM2 the transfer rate is almost 256 Mb/s.
scp 80Gblargefile VM2:/home/...
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178
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iperf3 not consistent across different OS'es
I have connected two rooms via a 10Gbit fiber connection. The connection has one MikroTik switch with four SFP+ on one end (room A) and an Ubiquiti Unifi 24 ports with two SFP+ (room B).
On Room A, I ...
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858
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append date and time before each line in a text log file in windows 10
I want to append date and time before each line in a text log file in windows
I run iperf command in cmd in windows 10.
iperf.exe -c192.168.5.199 -u -t4 -i1 -f Kbytes -w1024k -b1024k >> client-...
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76
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iPerf3 - normal and reverse measurement in the same instance
I can start a normal measurement (with 192.168.1.2 being the server) with
iperf3 -c 192.168.1.2
and a reverse measurement with
iperf3 -c 192.168.1.2 -R
Is there any way I can do both a normal and a ...
- 11
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196
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Getting 2g speeds on hyper-v VM through a 10g nic
I'm testing my speeds using IPERF as I've recently installed a 10G cisco switch and intel 10g NIC's on some servers to communicate with a nas server.
I noticed my reads and write were awful so I've ...
- 157
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51
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iptables tool to measure latency instead of bandwidth
I'm trying to measure the latency of having a lot of iptables rules.
I tried to use iperf but I think that bandwidth is not what i want.
Any help with this?
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379
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FreeNAS + LAGG Slow Transfer?
I built a new file server that should be way overbuilt for its purpose. It has 2 Intel(R) Xeon(R) CPU E5-2660 v3, with 128GB of ram and it is running LCAP through an Intel X540T2 network card to a ...
- 121
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Why is there a difference in speed of forward and reverse traffic over 10 G network in iperf tool
I have a 10G network setup between my two servers (say, Server1 and Server2) and I'm using iperf tool to measure the bandwidth of the network.
Here are test cases that I performed,
Test Case 1: (...
- 111
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514
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variable number of lost UDP packets reported by iperf, linux scheduling?
I am testing a connectivity with an iperf server (iperf version 2.0.13 (21 Jan 2019) pthreads) running on a Bananpi M2+ single-board computer (Debian, 5.1.1-BPI-Kernel #1 SM). For different target ...
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Why udp has lower throughput than tcp? [duplicate]
I am measuring the tcp and udp throughput by iperf3. I run iperf3 in virtual machines, one as server and the other as client. The VMs are connecting via 10 Gbps link. The results show that tcp get ...
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467
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Using trickle/trickled to limit bandwidth throughput of iperf3
I'm doing some throughput testing on some radio units that have narrow channel bandwidth settings (for example sub 250KHz bandwidth). During my testing of iperf3, I noticed that the slowest speed it ...
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3
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using Iperf3 to test upload and download
How to use Ipfer3 to test upload and download speed or in other words which data of the output given below represents upload and download speed ?
Iperf3 output
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using random ports with iperf/iperf3 [closed]
I am using Iperf/iperf3 -c remotehost which is
iPerf3 is a tool for active measurements of the maximum achievable bandwidth on IP networks. It supports tuning of various parameters related to ...
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559
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At Iperf3, TCP weird behavior
I am a newbie network engineer.
I did a small experiment with iperf3. But I run into a small problem.
(1) My question.
I think TCP flow do not act properly despite of its congestion control.
The flow ...
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43k
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How to start iperf3 server in UDP mode?
I would like to test UDP connectivity with iperf3 but do not know how to start it in UDP server mode.
iperf3 -s only opens a TCP socket:
root@srv ~# lsof -i -P | grep iperf3
iperf3 21030 ...
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2k
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socat tun device very low throughput
I was tinkering around with socat and tried to use socat for creating a TUN device for tunneling between two debian stretch servers. However, throughput seemed very low and comparing with iperf ...
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452
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Issues with Cisco IPSec VPN speed. Fast uploads, slow downloads from external to internal servers
We are using a Cisco ASA5516, configured with a IPsec (IKEv1) split tunnel VPN.
When uploading files to a server behind the firewall, the transfer speeds are normal (up to 10mbps).
When downloading ...
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3
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Why am I only achieving 2.5Gbps over a 10Gbe direct connection between 2 machines?
I have 2 machines directly connected to each other with a 7 foot Cat6a ethernet cable (included in the box of the NIC cards). The PCIe x4 NIC I bought and in both machines is this: https://www.amazon....
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How can iperf reporting packet loss in udp
Iperf is the well known tool to calculate throughput. When i tried udp throughput using iperf on my linuxpc, It reported that 10% of packet loss.
In UDP protocol, data gram did not receice any ...
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2k
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iperf3 UDP not reliable with iptables drop random
I'm performing some local test on my network with iperf3 using UDP connections between 2 Ubuntu 18.04 hosts. But it seems that the UDP iperf3 connections it is not robust to support a random packet ...
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2k
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Low bandwidth when Iperfing data thorugh IPSEC tunnel
We have two server connected next to each other. When we're iperfing each other through 'simple' physical interaces - we're getting ~5GB/S of bandwidth. But when im sending traffic through tunneled (...
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How can I use an iperf output and only grep 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 ...
- 113
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2
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3k
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Undefined iperf3 ports?
I am trying to identify all of the ports affiliated with an iperf3 UDP session and am noticing that the TCP handshaking uses an undefined(?) port on the iperf3 server.
Is there a way to specify all ...
- 537
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403
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Iperf2 capture received promiscous mode traffic Not Multicast
I want to capture all traffic in my Iperf server that I listen for promiscously, even if I am not the intended IP.
I know you can do this with Multicast addresses, but I do not want to follow that ...
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1k
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The FastNetMon client why not show the Incoming and Outgoing traffic?
I use VMWare created two VMs on my Windows Server.
two VM all are CentOS-7.2.
My FastNetMon version is bellow:
/opt/fastnetmon/fastnetmon --version
Version: 1.1.3 master git-...
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770
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I test the Iperf failed
In my Server(CentOS7.2, address is 103.193.202.2), I run the iperf server:
# iperf -u -s
------------------------------------------------------------
Server listening on UDP port 5001
Receiving 1470 ...
- 326
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427
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ieprf vs iperf3 metrics does not match
I am not a network expert but I was measuring the network between to physical hosts using iperf and I got different results depending of the version I was using.
Server configuration:
CPU:
...
- 205
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780
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How to measure bandwidth per cpu utilization [closed]
I'm trying to measure efficiency of the networking system and looking for a tool that either allows to limit max bandwidth for each test or, ideally, limit cpu utilization. At the end I need to have ...
- 131
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138
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Can ARP expire mid iperf connection?
If one runs an iperf connection between a node 'A' and a node 'B' is it possible that the arp entry expires from one of the nodes. [I have a simple mininet topology and while running an iperf ...
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