Iperf3 error unable to connect to server connection timed out

iperf3: error — unable to connect to server: Connection timed out #979

5% of time) keep seeing Connection time out on my test bed. If I retest it usually is not seen. I am trying to understand what it means by this error message «iperf3: error — unable to connect to server: Connection timed out» to help debug better. Below log snippet shows that the DUT is able to pass traffic on one port but failed on the other one. The connection time out message is persistent unless restart the whole test.

Version of iperf3:
iperf 3.1.3

Operating system (and distribution, if any):
Linux user-server-generic

18.04.1-Ubuntu SMP Thu Feb 7 14:06:04 UTC 2019 x86_64

The text was updated successfully, but these errors were encountered:

It looks like the log snippets show that you’re trying to run the same command twice. the first time it worked and the second time (same parameters) it didn’t. Correct?

Basically the error means that the client is trying to set up to the control connection (over TCP) to the server, but the client is not getting any response from the server (in other words it can’t set up that TCP connection). This can happen in cases where the server host is down or unreachable due to network routing or other issues like that. It’s usually not an intermittent thing.

I’m not sure how to interpret your comment of «able to pass traffic on one port but failed on the other one». Are there multiple network interfaces involved? If so, consider possible routing or host-based firewall issues. Is there a load-balancer involved (since you were apparently going to the same server IP address both times), and could that be an issue?

Finally, you’re using a version of iperf3 that’s almost four years old. Consider using a newer version (3.7 is current as of this writing), newer versions have many bug fixes and enhancements.

Источник

iperf3: error — unable to connect to server: Connection refused #1092

NOTE: The iperf3 issue tracker is for registering bugs, enhancement
requests, or submissions of code. It is not a means for asking
questions about building or using iperf3. Those are best directed
towards the iperf3 mailing list at iperf-dev@googlegroups.com or
question sites such as Stack Overflow
(http://www.stackoverflow.com/). A list of frequently-asked questions
regarding iperf3 can be found at http://software.es.net/iperf/faq.html.

Context

Version of iperf3: iperf 3.7 (cJSON 1.5.2)

Hardware: Intel CPU > i5-9300, Memory > 16G

Operating system (and distribution, if any): Windows 10 and running Ubuntu 20.04 LTS(WSL 2)

Please note: iperf3 is supported on Linux, FreeBSD, and macOS.
Support may be provided on a best-effort basis to other UNIX-like
platforms. We cannot provide support for building and/or running
iperf3 on Windows, iOS, or Android.

• Other relevant information (for example, non-default compilers,
  libraries, cross-compiling, etc.):

Please fill out one of the «Bug Report» or «Enhancement Request»
sections, as appropriate.

Bug Report

Now I’m running iperf3 on two machine. and Two machines are running windows 10, WSL 2, Ubuntu 20.04.
iPerf3 version has same both server and client machine. iperf 3.7

Two machine is possible icmp request and reply without any problem.
But when I tried to start iperf3 from client I met this error.

1. iPerf3 Server screen(Server IP is 192.168.200.253)
   root@SHINCH01-15U560:/usr/bin# iperf3 -s

Server listening on 5201

1. iPerf Client Screen.(Client IP is 192.168.200.251)
   root@CHANGHEESHIN01-5501I5:/usr/bin# iperf3 -c 192.168.200.253 -i 2
   iperf3: error — unable to connect to server: Connection refused

I already shutdown windows firewall and ubuntu firewall with the following command

root@CHANGHEESHIN01-5501I5:/usr/bin# ufw disable
Firewall stopped and disabled on system startup
root@CHANGHEESHIN01-5501I5:/usr/bin# ufw status
Status: inactive

Can I know what is root cause?

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Источник

iperf3: error — unable to receive control message: Connection timed out #320

I am having an issue with iperf3, where at the end of a timed test session, the connection between the iperf3 server and client does not close correctly.

The test bed looks like this:

• Command Server (128.0.0.2) — Connected to a dumb switch. This is used to
  issue commands to the clients
• Switch
• Client (128.0.1.9) — A Raspberry Pi with the latest version of iperf3. One
  interface is connected to the dumb switch, the other is connected to a gateway
• Gateway (192.168.0.1) — Gateway for traffic to and from the server
• Server (10.123.126.2) — A Debian machine running an iperf3 server

Expected behaviour

The iperf3 client should open a session with the iperf3 server, report some
data to stdout every ith second, close the session, and report some more data

What is Actually Happening

The iperf3 client opens a session with the iperf3 server, reports some data to
standard out every ith second up until the last few seconds of the run, then
hangs for about 15 minutes before reporting this message:

This bug occurs whenever the run lasts for more than 10 minutes or so (i.e.,
whenever the -t >= 600).

Recreating the bug

Sys info

No matter what the -t value is, as long as it is over 600 or so, the same behaviour is exhibited — iperf3 runs until just a few seconds before the run is scheduled to end, waits for about 15 minutes, then complains about not receiving a control message because of a Connection timeout.

SSH TCPKeepAlive is on. I can confirm using tcpdump that there is network activity over that port right up until the end of the run is scheduled, and then nothing during the timeout period. I have tried to recreate the problem using pv and netcat, and am unable to, which leads me to believe that this is a iperf3 problem.

Not sure how to move forward. Could you suggest another setting to look at? Perhaps this is a bug with iperf3?

The text was updated successfully, but these errors were encountered:

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iperf server on debian squeeze #133

From wpmccormick on January 16, 2014 05:37:06

What steps will reproduce the problem? 1. fresh compile on debian squeeze
2. iperf3 -s or iperf3 -s -D
3. netstat -a; tcp/5201 is listening What is the expected output? What do you see instead? nmap 172.16.125.5 shows no port open
cannot connect clients except from the same machine What version of the product are you using? On what operating system? root@SAM.304-ms:/home/fiber# iperf3 -v
iperf version 3.0.1 (10 January 2014)
Linux SAM 2.6.33 #1 PREEMPT Wed Jun 30 11:35:16 EDT 2010 i586 GNU/Linux Please provide any additional information below. I thought that perhaps iperf might be binding to eth0, an unused dhcp port, but I think I ruled that out by swapping eth0 & eth1.

Client seems to work ok.

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From wpmccormick on January 16, 2014 08:55:13

In trying a different port (I used 11111), nmap did show the port as open but a non local client still couldn’t connect to it.

From bmah@es.net on January 16, 2014 09:24:04

If you can connect to the iperf server locally but not from a different host, this sounds like a firewall problem. By default the iperf server doesn’t bind to any particular port (it would if you use the -B option), so there’s no particular reason for iperf to take connections via one interface versus another.

When you say «cannot connect clients except from the same machine» what error message do you get from your client?

Any way you can tell if you have a firewall configured on this host and if so what its ruleset is? (I wish I could give more specific guidance but I’m more of a FreeBSD person, most of my Linux experience is CentOS.)

From wpmccormick on January 16, 2014 13:48:21

I agree it sounds like a firewall issue, but the fact that client and server are at the opposite ends of a VPN, and also that the the machine where the iperf server is running has NO iptables config (below), leaves me scratching my head. Even though I can connect locally, nmap still does not show the port as being open. Just to prove that this isn’t a fire wall issues, I can connect to a server that I wrote that is listening on tcp/11111. I didn’t do anything special to make this work.

/* testing client connection to another server app . it works */
root@fibuntu:

# telnet 172.16.125.5 11111
Trying 172.16.125.5.
Connected to 172.16.125.5.
Escape character is ‘^]’.
read|NO_FAN_FAULT_M1
!read|NO_FAN_FAULT_M1|1
disconect
ERROR : invalid command : disconect
quit
ERROR : invalid command : quit
disconnect

Connection closed by foreign host.

/* start iperf, the [3] is something I added so I could see what the sock fd was */
root@SAM.304-ms:/home/fiber# /usr/local/bin/iperf3 -s -4 -V
iperf version 3.0.1 (10 January 2014)

Linux SAM 2.6.33 #1 PREEMPT Wed Jun 30 11:35:16 EDT 2010 i586 GNU/Linux

Server listening on 5201 [3]

/* from another console, see what iperf is doing /
root@SAM.304-ms:/home/fiber# netstat -ap| grep 5201
tcp 0 0 *:5201 *: LISTEN 1099/iperf3
root@SAM.304-ms:/home/fiber# ps aux|grep iperf
root 1099 0.0 0.0 1728 544 pts/0 S+ 16:41 0:00 /usr/local/bin/iperf3 -s -4 -V
root 1108 0.0 0.0 3284 724 pts/2 S+ 16:41 0:00 grep iperf

/* try to connect to the iperf server across and OpenVPN tunnel, server to client*/
root@fibuntu:

# /usr/local/bin/iperf3 -c 172.126.125.5 -p 5201 -V -t 60
iperf version 3.0.1 (10 January 2014)
Linux fibuntu 3.5.0-39-generic #60-Ubuntu SMP Tue Aug 13 18:33:05 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
iperf3: error — unable to connect to server: Connection timed out

/* see what ports are open on the remote side */
root@fibuntu:

# nmap -sT 172.16.125.5

Starting Nmap 6.00 ( http://nmap.org ) at 2014-01-16 15:33 CST
Nmap scan report for 172.16.125.5
Host is up (0.083s latency).
Not shown: 995 closed ports
PORT STATE SERVICE
21/tcp open ftp
22/tcp open ssh
53/tcp open domain
80/tcp open http
11111/tcp open vce

Nmap done: 1 IP address (1 host up) scanned in 11.82 seconds

/* see what ports are open on the local side */
root@SAM.304-ms:/home/fiber# nmap -sT localhost

Starting Nmap 5.00 ( http://nmap.org ) at 2014-01-16 16:34 EST
Interesting ports on localhost.localdomain (127.0.0.1):
Not shown: 994 closed ports
PORT STATE SERVICE
21/tcp open ftp
22/tcp open ssh
53/tcp open domain
80/tcp open http
111/tcp open rpcbind
11111/tcp open unknown

Nmap done: 1 IP address (1 host up) scanned in 0.83 seconds

/* check iptables */
root@SAM.304-ms:/home/fiber# iptables -S
-P INPUT ACCEPT
-P FORWARD ACCEPT
-P OUTPUT ACCEPT
root@SAM.304-ms:/home/fiber# iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

Источник

Iperf3 error client connection refused #758

NOTE: The iperf3 issue tracker is for registering bugs, enhancement
requests, or submissions of code. It is not a means for asking
questions about building or using iperf3. Those are best directed
towards the iperf3 mailing list at iperf-dev@google-groups.com or
question sites such as Stack Overflow
(http://www.stackoverflow.com/). A list of frequently-asked questions
regarding iperf3 can be found at http://software.es.net/iperf/faq.html.

Context

Version of iperf3: 3.1.3

Hardware: CPU 2.6HZ

Operating system (and distribution, if any): windows 10

Please note: iperf3 is supported on Linux, FreeBSD, and macOS.
Support may be provided on a best-effort basis to other UNIX-like
platforms. We cannot provide support for building and/or running
iperf3 on Windows, iOS, or Android.

• Other relevant information (for example, non-default compilers,
  libraries, cross-compiling, etc.):

Please fill out one of the «Bug Report» or «Enhancement Request»
sections, as appropriate.

Bug Report

Expected Behavior
it has to link a connectivity between Server machine and client machine to showcase transfer rate and bandwidth

Actual Behavior
its throwing an error called iperf3 cannot be connected connection refused

Steps to Reproduce

Please submit patches or code changes as a pull request.

Enhancement Request

If submitting a proposed implementation of an enhancement request,
please use the pull request mechanism.

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Источник

I want to get iperf3 to benchmark a simple wireguard setup on my LAN.  I have two machines, foo is 192.168.1.228 and bar is 192.168.1.112.

These IP addresses are fully functional on their respective eth0 interfaces.  Each one also has a wg0 interface configured as shown below.  I can get iperf3 to work over the non-wireguard interfaces, but not over the wireguard interfaces.  Am I using iperf3 wrong?  Did I misconfigure wg?

Details
Here are the /etc/wireguard/wg0.conf files for both machines (I don’t care if the public/private keys are present/this is only a test environment and it will allow others to simply copy/paste if they want to test as well):

On foo:

[Interface]
Address = 10.0.9.15/24
SaveConfig = true
ListenPort = 500
PrivateKey = kLac+M+JJJ+gpsKo1DeUyfuwfDwGeKMj81+M3Z3mUkw=

[Peer]
PublicKey = y6DrsFVIgqBMc8joSuEytCpQEywk5dPKRoeLZZC9H34=
AllowedIPs = 10.0.9.16/32

On bar:

[Interface]
Address = 10.0.9.16/24
SaveConfig = true
ListenPort = 500
FwMark = 0xca6c
PrivateKey = 4EwMqSyvLaHrv5JvAAyKnmdbw9UN4rsjydkPXb5ll28=

[Peer]
PublicKey = SkBs9t96znOr+d60tgPlXkp7z6YABvfxD9KNVzZIP3I=
AllowedIPs = 0.0.0.0/0
Endpoint = 192.168.1.228:500

Again, both wireguard interfaces are up and connected.  For example, on foo:

# wg
interface: wg0
  public key: SkBs9t96znOr+d60tgPlXkp7z6YABvfxD9KNVzZIP3I=
  private key: (hidden)
  listening port: 500

peer: y6DrsFVIgqBMc8joSuEytCpQEywk5dPKRoeLZZC9H34=
  endpoint: 192.168.1.112:500
  allowed ips: 10.0.9.16/32
  latest handshake: 10 minutes, 41 seconds ago
  transfer: 32.45 KiB received, 8.24 KiB sent

If I run iperf3 in server mode on foo and in client mode on bar, it works as expected using the non-wireguard interfaces:

On foo:

% iperf3 -s -B 192.168.1.228
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------
Accepted connection from 192.168.1.112, port 58575
[  5] local 192.168.1.228 port 5201 connected to 192.168.1.112 port 46261
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec   107 MBytes   900 Mbits/sec
[  5]   1.00-2.00   sec   112 MBytes   939 Mbits/sec
[  5]   2.00-3.00   sec   112 MBytes   940 Mbits/sec
[  5]   3.00-4.00   sec   112 MBytes   938 Mbits/sec
[  5]   4.00-5.00   sec   112 MBytes   940 Mbits/sec
[  5]   4.00-5.00   sec   112 MBytes   940 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-5.00   sec   596 MBytes  1.00 Gbits/sec                  receiver
iperf3: the client has terminated

On bar:

% iperf3 -c 192.168.1.228 -B 192.168.1.112
Connecting to host 192.168.1.228, port 5201
[  5] local 192.168.1.112 port 46261 connected to 192.168.1.228 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   113 MBytes   950 Mbits/sec    0    281 KBytes
[  5]   1.00-2.00   sec   112 MBytes   939 Mbits/sec    0    296 KBytes
[  5]   2.00-3.00   sec   112 MBytes   938 Mbits/sec    0    296 KBytes
[  5]   3.00-4.00   sec   112 MBytes   938 Mbits/sec    0    296 KBytes
[  5]   4.00-5.00   sec   112 MBytes   944 Mbits/sec    0    308 KBytes
^C[  5]   5.00-5.33   sec  36.7 MBytes   939 Mbits/sec    0    308 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-5.33   sec   598 MBytes   942 Mbits/sec    0             sender
[  5]   0.00-5.33   sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated

When I try using the IP addresses of the respective wireguard interfaces, I get nothing:

On foo:

% iperf3 -s -B 10.0.9.15
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------

On bar:

% iperf3 -c 10.0.9.15 -B 10.0.9.16
iperf3: error - unable to connect to server: Connection timed out

Last edited by graysky (2018-12-18 22:49:53)