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Questions tagged [iperf]

128 questions
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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 byte datagrams UDP buffer size: 208 KByte…
aircraft
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How to measure bandwidth per cpu utilization

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 an answer like "for 10% CPU bandwidth is…
Kentzo
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Low network speed with small packets

Using iperf3 to test the network with --length 1000 --no-delay: iperf3 --interval 1 --time 3 --no-delay --length 1000 --parallel 100 --client 10.0.0.3 Result: [SUM] 0.00-3.00 sec 835 MBytes 2.33 Gbits/sec 13 sender [SUM] …
benji
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How to increase bandwidth of bonding interface in mode 6?

I am new to Linux Bonding Driver. I have configured a bond in mode 6 which combines 2 ethernet interfaces. Their individual bandwidth is 937Mbps and 700 Mbps. But when both the interfaces are up, the bandwidth of the bonding interfacs is always that…
Raunak
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What network setting could impact iperf3 results?

I am making some bandwidth tests to set a baseline for some other tests and I have a behaviour I cannot understand. The tests are done with iperf3 on Linux (with and without -R to get both up- and down-stream). I called the machines "home" and…
WoJ
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slow single connection between two otherwise fast machines

I'm having trouble with larger file transfers from one of our virtual servers to our office network. The virtual server acts as a VPN server, therefore we call it "VPN", but the usage of VPN is not of issue here, I used direct connections for the…
Roger Lehmann
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How to set the UDP Packet Size with iperf3?

How to set the UDP Packet Size with iperf3? The flag "-M" does not work with iperf3. Is there an alternative?
Jimmy88
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Why the bandwidth is not ~10G?

I originally posted on "Network Engineering", but I was told to ask here. I have 2 servers connected with 10G cable between them directly. I need to know that the connection is good and it has indeed 10G throughput. If not how I can check what is…
theateist
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iperf actual send rate always lower than the expected target bandwidth until some equilibrium reached. Why?

I did an UDP iperf 2.0.5-Ubuntu test between two VMs on the same hypervisor. As can be seen in the iperf output below I started my first test with "-b 686M" flag. However, iperf reported that it was able to send traffic only at 633Mbps (92% of…
john1234
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Strange iperf3 behaviour with UDP streams

I am using iperf3 verson 3.0.11 to measure the throughput of a UDP stream between two virtual machines. The virtual machines are deployed via OpenStack. Of the physical hosts, one is located in Bratislava, the other one in Ljubljana. Network wise,…
User
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No package iperf3 available CentOS

I'm trying to install iperf3 on a server to run some tests... Unfortunately I cannot. What do I need to do? Enable a repo or download a rpm file with wget? [root@localhost hodor]# yum install iperf3 Loaded plugins: fastestmirror, langpacks Loading…
Menelaos
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Iperf Tcp Client and Server

I'd really like to know why the bandwith in the client is higher than the server, i can´t find the answer explaining why this happens. Thank you, Tiago Melancia Values of the bandwidth: Client Server
Tiago Melancia
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Network Traffic fluctuating, even with loopback

I am using iperf tool to benchmark my network interfaces on two identical machines (Dell Blade Server M620). Both have given different results. On 1st machine, I ran server and clients as: Server ==> iperf -s -B 172.17.250.200 Server listening on…
Waqas
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iperf shows 200Mb when host is the client, but 900Mb when it is the server

On host 'abc' I run: iperf -s -w 256k On host 'xyz' I run: iperf -c -w 256k And I get 900Mb. When I reverse the commands, making 'abc' the client, I get 200Mb. This means that abc's upload speed maxes at 200Mb. There are no devices between these…
Ian Ling
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Is iperf valid to measure network performance?

We are investigating performance issues in one of our software deployment between our application servers (Windows) and our Redis instances (Linux). On a 10 Gbits/s link single TCP connections can apparently only reach 10 Mbits/s. Opening several…
ereOn
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