Ethernet port has no lights turned on

[Hewyn]

Hello there!

I have just received my first raspberry pi today. It is the 3 B+ model.

This evening, I tried to use the ethernet port and it did not work.
First, there is no lights turning on after I plugged the cable (with the raspberry pi turned on).
Second, I tried to configure it but it did not help.
I followed the steps using different sites.
One of them is this one https://www.mathworks.com/help/supportp ... dress.html

I also tried different ethernet cables, all of them are working well with other devices.

I am wondering if I have got a faulty raspberry pi or if I am not configuring it correctly?

Thank you very much for your help.

[wh7qq]

The ethernet port on the RPi should connect automatically with no configuration required on the part of the user. That no lights turn on on the RJ-45 connector indicates that there is no connection. If the cable is not faulty, it is probably a problem on the other end...whatever you have connected to. Rarely, you will get an RPi that is defective but you need to check out everything else, especially the device on the other end. Try connecting the RPi directly to the modem or router that is getting the connection with the ISP, changing the ports on the router or AP. If you are connecting to an ethernet connection on a laptop, the configuration of the connection on that device is what you need to look at. The RPi will attempt to get an IP assignment from whatever it is connected to but no IP, no connection.

[DougieLawson]

Do you have a power supply that's up to the job? The first things to stop working with a weedy supply are the ethernet & USB.

Also are you using the very latest Raspbian?

[LTolledo]

Same thing happened to my spare RPi3B+ using an unmarked Flat Ethernet cable

when the same cable is plugged to an RPi3B the lights turned on (so does in the Hub)
but when I replugged it to an RPi3B+, lights out!
replaced the cable with another, same results
repeated the check 3 times, same results

then I replaced the cable with a one marked "CAT6 Flat Ethernet Cable"
Ethernet port lights turned on (so does in the hub) and the Ethernet Icon turned on as well.

[RaTTuS]

... "CAT6 Flat Ethernet Cable"
...

Just FYI you cannot have flat cat6 cable
but the rest is interesting

[LTolledo]

... "CAT6 Flat Ethernet Cable"
...

Just FYI you cannot have flat cat6 cable
but the rest is interesting

But I actually have 2 of those, one is 1 meter in length, another is 5 meters in length, both clearly marked as "CAT.6 FLAT CABLE RoHS"

as reference this is the 5meter one that I used
https://www.amazon.co.jp/gp/product/B01 ... UTF8&psc=1

[RaTTuS]

I'm 99% sure that cat6 needs the pairs to be twisted and the twisted pairs to be twisted
flat cable can be made to be similar in xtalk to TP cables but it cannot be sold as cat6 [offically]

I've personally have no issues with flat cables , it's just installers and wire men do ....

[LTolledo]

Anyway those flat Ethernet cables work properly with my RPi3B+.... and that is important to me....

I'll use what works, wont use what doesn't... simple as that.

[DougieLawson]

... "CAT6 Flat Ethernet Cable"
...

Just FYI you cannot have flat cat6 cable
but the rest is interesting

Who cares? If we assume the OP has tested whatever cable he/she is using means your meta-discussion is off-topic.

Can we concentrate on offering solutions
that might help ratherr than discussing things that are 100% irrelevant?

[Hewyn]

First, I would like to thank you all for your help.

The ethernet cables I tested are plugged in other devices and are working well.
However, they don't work with the raspberry pi.
I found another cable in a drawer and it worked perfectly.
I don't understand why the previous cables are not working with the raspberry pi but I am glad that the issue is resolved.

Thanks again.

[pcmanbob]

A 1000 byte network requires all 8 cores of the LAN cable to be connected, its possible that the cables you tried were just 4 core cables or have a faulty core within them.
Desktop PCs and laptops will often work even with these cables because they will automatically switch to 10/100 byte networking, which only requires 4 working cores.

To test a cable you are always better to use a cable tester.

[Burngate]

Not wanting to divert the thread into off-topic discussions, but since the OP has resolved his issue ...

...
Desktop PCs and laptops will often work even with these cables because they will automatically switch to 10/100 byte networking, which only requires 4 working cores.

Are you saying the Pi won't automatically switch? If not, why not?

[pcmanbob]

So from my own testing.

Using a LAN cable that has cores 7 & 8 which are faulty and cores 1 to 6 which are working fine, using a pi3B+

Plugging cable in to a 10/100mb switch pi connects ok but at 100mb, plugging same pi and cable in to 10/100/1000mnb switch pi does not connect, even if you boot the pi from cold with this connection.

So it looks to me that if you have a pi3B+ connected to a 10/100/1000mb LAN port and you have a core faulty in your LAN cable you will not get a connection between the pi and the network, at least on my switch which is a Netgear ProSafe GS116.

I have no idea why the pi does not switch to 100mb networking under these conditions.