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Dedibox Network - Troubleshooting
Running network tests
To diagnose a network issue, you can perform different tests.
An MTR test combines the functions of traceroute and ping on all points between two machines.
When running an MTR test, it is important to do it in both directions:
- From the server to the IP of your connection
- From your connection to the server
You have to check that the
mtr packet is installed.
sudo apt-get install mtr
sudo yum install mtr
You have to install WinMTR on your server.
Download the application from its project page.
Extract the archive and run the executable.
Enter the target (IP) of your test in the Host textbox, then click on Start. Wait one or two minutes before you stop the test. You can then make a screenshot or export the result with the functions of the software.
Example of MTR between a Scaleway Dedibox server and
free.fr:root@163-172-30-2:~# mtr --report free.frStart: Sun May 1 16:23:57 2016HOST: 163-172-30-2 Loss% Snt Last Avg Best Wrst StDev1.|-- 163-172-30-1.rev.poneytel 0.0% 10 0.5 0.5 0.4 0.5 0.02.|-- 18.104.22.168 0.0% 10 1.6 1.0 0.9 1.6 0.03.|-- 22.214.171.124 0.0% 10 1.2 1.4 1.2 2.6 0.34.|-- th2-crs16-1-be1503-t.intf 0.0% 10 1.3 1.3 1.1 1.4 0.05.|-- p11-crs16-1-be1001.intf.r 0.0% 10 4.5 3.0 1.4 4.5 0.76.|-- p11-9k-1-be1000.intf.rout 0.0% 10 1.5 2.1 1.4 3.5 0.67.|-- bzn-9k-2-sys-be2001.intf. 0.0% 10 1.7 1.8 1.6 2.8 0.08.|-- www.free.fr 0.0% 10 1.2 1.2 1.2 1.2 0.0
The results show:
- The percentage of lost packets
- The number of packets sent during the test (here 10)
- The latency of the last packet sent between two points
- Average latency for all packets sent between two points
- Latency of the best result
- Latency of the worst result
With an IPERF test you can check the available bandwidth of your server.
The iperf server ping.online.net has several ports available (5200-5209). If the server is busy on the default port, you can specify another port using the
-p flag, for example:
-p 5203 (5204, 5205, etc.).
If iperf is not yet installed on your server, you can install it with the following command:
sudo apt-get install iperf3
yum apt-get install iperf3
Then launch the test:
root@163-172-30-2:~# iperf3 -c ping.online.net -R------------------------------------------------------------Client connecting to ping.online.net, TCP port 5001TCP window size: 85.0 KByte (default)------------------------------------------------------------[ 3] local 126.96.36.199 port 36490 connected with 188.8.131.52 port 5001[ ID] Interval Transfer Bandwidth[ 3] 0.0-10.0 sec 1.10 GBytes 943 Mbits/secIf your server is located at Amsterdam execute: root@163-172-30-2:~# iperf3 -c ping-ams1.online.net -R
- Download the tool from its website.
- Choose the latest version and download the file.
- Extract the file.
- Open a terminal and run the following command:
\iperf3.exe -c ping.online.net -p 5203
The results show:
- Sampling interval in seconds
- Amount of data transferred during the test
- Available bandwidth of your server
If your server’s network port is off
Sometimes when you change the mode of your dedicated server from normal to rescue mode during the reboot of a server, you may see the following error message in your console:
Your server’s network port is off. If you just asked for a server reboot, or to boot in rescue or test mode, this message will only be displayed for a few seconds. Otherwise, our network equipment may be on protective mode due to non-authorized traffic. In this case, please ask the support team to unlock your server.
If this message is visible for a longer period or cycles every 5 minutes, it means your server is either distributing unauthorized traffic in the style of DHCP, distributing a MAC address that is not assigned to the server, ARP requests, too many requests per second in sending or receiving on your server.
If you continue to see this message, empty the cache of your browser as the old page may be kept in it. Alternatively, you can reload the page several times until the message disappears.
When setting up the WAN interface on a PfSense firewall you should disable auto-configuration, as it might cause an IPv6 packet flood shutting down your server’s network port. If your network ports do not become available after a few minutes, you need to contact the support.