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):

power OFF the router
wait 2-5 minutes
power ON the wireless AP
wait 5 more minutes
retry the connection

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

SSH into the device and enter:

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

when using a USB dongle execute:

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.

ensure network tools are installed
- Settings
- Add-ons
- Install from repository
- CoreELEC Add-on repository
- Program add-ons
- Network tools

connect via SSH

to place a device in receiving mode run:

iperf3 -s

to place a device in sending mode run:

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.