Table of Contents

Network Troubleshooting

To troubleshoot network issues, ensure the device is directly connected to the Internet Gateway Device (router)


Basic Network Problems

Network issues can be hard to diagnose. This section provides some basic Network troubleshooting tips.


First step

Power cycle all devices connected to the network, starting with the gateway device.

Wired Network

Cable The cable which is used to connect two devices can become faulty, shorted out, or physically damaged
Connectivity The port or interface on which the device is connected or configured can be physically damaged or powered down, preventing the source host to communicate with the destination host
Bandwidth Saturation Over-utilizing a link can increase the capacity or traffic on a device to more than its carrying capacity. This can cause overload conditions where the device will start behaving abnormally
Configuration Configurations errors, IP looping, port settings, IP collisions, bad routing tables and other configuration-related issues can cause network errors
Network IP Improper configuration of IP addresses, subnet masks and routing IPs to the next hop can cause the source to be unable to reach the destination IP through the network
Software Issues Software compatibility issues and version mismatches can interrupt the transmission of IP data packets between source and destination

Cable Performance

Category Shielding Max Frequency Max Data Rate (*)
Cat 3 Unshielded 16 MHz 10 Mbps
Cat 5 Unshielded 100 MHz 100 Mbps
Cat 5e Unshielded 100 MHz 1 Gbps
Cat 6 Shielded/Unshielded 250 MHz 1 Gbps
Cat 6a Shielded/Unshielded 500 MHz 10 Gbps
Cat 7 Shielded 600 MHz 10 Gbps
Cat 8.1 Shielded 2000 MHz 25 Gbps
Cat 8.2 Shielded 2000 MHz 40 Gbps

(*) At 100 meters


Wireless Network

If the wireless connection suddenly stops working, before trying anything else, restart the wireless Access Point (usually the router):

In most cases, this should fix the issue and allow the device to get back online.

If this doesn’t help, delete the network connection entirely from the device (Forget This Network), then add the connection anew.


Collecting Device Information

udevadm info /sys/bus/sdio/devices/* | paste
lsusb

Provide the generated log(s) when requesting support


iPerf

iPerf 3 is a tool for active measurements of the maximum achievable bandwidth between devices on an IP network.

iperf3 -s
iperf3 –c remotehost

Example: iperf3 –c 192.168.0.4

-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------
Accepted connection from 192.168.0.4, port 52180
[  5] local 192.168.0.7 port 5201 connected to 192.168.0.4 port 52182
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   107 MBytes   895 Mbits/sec    0    362 KBytes
[  5]   1.00-2.00   sec   113 MBytes   946 Mbits/sec    0    378 KBytes
[  5]   2.00-3.00   sec   111 MBytes   935 Mbits/sec    0    395 KBytes
[  5]   3.00-4.00   sec   112 MBytes   941 Mbits/sec    0    436 KBytes
[  5]   4.00-5.00   sec   112 MBytes   939 Mbits/sec    0    436 KBytes
[  5]   5.00-6.00   sec   112 MBytes   942 Mbits/sec    0    436 KBytes
[  5]   6.00-7.00   sec   112 MBytes   944 Mbits/sec    0    436 KBytes
[  5]   7.00-8.00   sec   112 MBytes   941 Mbits/sec    0    436 KBytes
[  5]   8.00-9.00   sec   112 MBytes   941 Mbits/sec    0    436 KBytes
[  5]   9.00-10.00  sec   112 MBytes   942 Mbits/sec    0    436 KBytes
[  5]  10.00-10.04  sec  4.72 MBytes   951 Mbits/sec    0    436 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.04  sec  1.10 GBytes   937 Mbits/sec    0             sender
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------
Accepted connection from 192.168.0.4, port 52184
[  5] local 192.168.0.7 port 5201 connected to 192.168.0.4 port 52186
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec   104 MBytes   874 Mbits/sec
[  5]   1.00-2.00   sec   108 MBytes   909 Mbits/sec
[  5]   2.00-3.00   sec   109 MBytes   913 Mbits/sec
[  5]   3.00-4.00   sec   109 MBytes   913 Mbits/sec
[  5]   4.00-5.00   sec   108 MBytes   910 Mbits/sec
[  5]   5.00-6.00   sec   108 MBytes   904 Mbits/sec
[  5]   6.00-7.00   sec   108 MBytes   903 Mbits/sec
[  5]   7.00-8.00   sec   108 MBytes   903 Mbits/sec
[  5]   8.00-9.00   sec   108 MBytes   902 Mbits/sec
[  5]   9.00-10.00  sec   108 MBytes   906 Mbits/sec
[  5]  10.00-10.04  sec  4.60 MBytes   897 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-10.04  sec  1.06 GBytes   904 Mbits/sec                  receiver
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------

For command line options and more information, please consult the iPerf3 user documentation.


Speed Tester

This Kodi add-on tests the Internet bandwidth and reports both download and upload speeds as well as latency.

Installation

Install the Speed Tester Addon from the Kodi Addon manager:

Team CoreELEC provides no support for 3rd party applications.

More resources

Software Testing Help: Basic Network Troubleshooting Steps And Tools

DNSstuff: Network Troubleshooting: Steps, Techniques, & Best Practices

CompTIA: A Guide to Network Troubleshooting

NetworkAcademy.io: Ethernet Fundamentals