Server Fault Stack Exchange
Server Fault Stack Exchange

Questions tagged [iperf]

128 questions
1
vote
0 answers

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 the actual bandwidth assigned of 1 Gbits/s I…
hwfanatic
  • 21
  • 2
1
vote
1 answer

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 rates when the transferred data gets written to file.…
pdp
  • 778
  • 1
  • 7
  • 16
1
vote
0 answers

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 10GB (INTEL X540-AT2)and 2 X 1GB (INTEL…
skb007
  • 136
  • 4
  • 6
1
vote
0 answers

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/myuser Then I remove the file from VM1 and, always in…
Salvatore D'angelo
  • 121
  • 4
1
vote
0 answers

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 reverse measurement one after another without…
Kaiser
  • 11
  • 1
  • 3
1
vote
2 answers

Command line based IP traffic generator

Does anyone know of a command line based traffic generator which can produce IP traffic so that we cant test QOS feature on DSL modem . It would be good if we can set the dscp marking in the IP packet . Curently we are using Iperf but we can't…
Vidya
  • 347
  • 1
  • 6
  • 19
1
vote
0 answers

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?
PRVS
  • 135
  • 1
  • 9
0
votes
1 answer

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 bandwidths I observed different rates of packet…
BigK
  • 33
  • 1
  • 5
0
votes
1 answer

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 would ever transfer at despite setting a bandwidth…
Aaron Hesse
  • 1
0
votes
1 answer

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 decrease its rate due to congestion ( flow rate >…
nimdrak
  • 29
  • 1
  • 7
0
votes
1 answer

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 files from the server, it's sitting around 100kbps…
ChrisKnowles
  • 101
0
votes
1 answer

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 drop of 0.1? When executing the iperf3 tests, the…
user886869
  • 245
  • 1
  • 2
  • 10
0
votes
1 answer

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 (strongswan) GRE interface. Im getting only…
Edvinas
  • 63
  • 8
0
votes
2 answers

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 of the ports used for an iperf3 test? Illustrating…
Nate
  • 557
  • 2
  • 8
  • 16
0
votes
1 answer

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 way: multicasting on Wifi incurs a throughput loss I…
Daniël Schoonwinkel
  • 1
  • 1
1 2 3
…
8 9