lorithai
Posts: 6
Joined: Tue Mar 01, 2016 7:02 pm

Raspberry pi doesn't get ethernet internet from router

Sat Sep 14, 2019 4:31 pm

Hi

Problem
I am trying to connect a rasbperry pi 3 B+ with an ethernet cable to a router which gets internet through a sim card. The raspberry pi seems to be able to connect to the router, but there is no internet.

Other devices are able to connect to this router just fine and the raspberry pi can connect to other access points, but not this one.

The GUI shows that the raspberry pi has gotten an ip4 address, but the ifconfig shows no inet (just inet6) and worse of the internet doesn't work.

Is there a way to diagnose and fix this problem?

gui
Image

ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::ba27:ebff:feb5:d2ea prefixlen 64 scopeid 0x20<link>
ether b8:27:eb:b5:d2:ea txqueuelen 1000 (Ethernet)
RX packets 396 bytes 26410 (25.7 KiB)
RX errors 0 dropped 326 overruns 0 frame 0
TX packets 144 bytes 19421 (18.9 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0


other details
Using raspbian GNULinux 10 (stretch), fresh install

Regards

Edit: Updated linux version
Last edited by lorithai on Sat Sep 14, 2019 5:42 pm, edited 1 time in total.

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B.Goode
Posts: 8514
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Location: UK

Re: Raspberry pi doesn't get ethernet internet from router

Sat Sep 14, 2019 4:51 pm

The GUI shows that the raspberry pi has gotten an ip4 address



No, not really.


That is a 'fall back' default address that shows you asked for an address allocated by a DHCP server but didn't get a valid reply.

So, symptomatic of a faulty connection between your RPi and the network infrastructure, or a DHCP server that for some reason has not responded to your request. Suggest power cycling the router, and swapping the utp/rj45 Ethernet cable for one proven to work, connected to a network outlet known to work.

(And unrelated to this issue, is there a reason why you have done a fresh install of a superceded Operating System?)

lorithai
Posts: 6
Joined: Tue Mar 01, 2016 7:02 pm

Re: Raspberry pi doesn't get ethernet internet from router

Sat Sep 14, 2019 5:41 pm

B.Goode wrote:
Sat Sep 14, 2019 4:51 pm
The GUI shows that the raspberry pi has gotten an ip4 address



No, not really.


That is a 'fall back' default address that shows you asked for an address allocated by a DHCP server but didn't get a valid reply.

So, symptomatic of a faulty connection between your RPi and the network infrastructure, or a DHCP server that for some reason has not responded to your request. Suggest power cycling the router, and swapping the utp/rj45 Ethernet cable for one proven to work, connected to a network outlet known to work.

(And unrelated to this issue, is there a reason why you have done a fresh install of a superceded Operating System?)
Thanks for the reply

Oh, i thought that was the newest, but i see now i must have used the wrong file while flashing. Testing with the newest version (10 (buster)) still gives the same result.

The cable i am using is working for other machines to this router as well as for the raspberry pi when connecting to other routers.

I have power cycled the router which didn't work. I'll get back when i try a different cable.

lorithai
Posts: 6
Joined: Tue Mar 01, 2016 7:02 pm

Re: Raspberry pi doesn't get ethernet internet from router

Sat Sep 14, 2019 6:00 pm

B.Goode wrote:
Sat Sep 14, 2019 4:51 pm
The GUI shows that the raspberry pi has gotten an ip4 address



No, not really.


That is a 'fall back' default address that shows you asked for an address allocated by a DHCP server but didn't get a valid reply.

So, symptomatic of a faulty connection between your RPi and the network infrastructure, or a DHCP server that for some reason has not responded to your request. Suggest power cycling the router, and swapping the utp/rj45 Ethernet cable for one proven to work, connected to a network outlet known to work.

(And unrelated to this issue, is there a reason why you have done a fresh install of a superceded Operating System?)
With Buster installed i powercycled the router, tested the cable on another router (it works on other devices, but not the pi) and changing for another ethernet cable (which i also tested with the same results) the problem still remains.

Is there a way to tell if the pi doesn't get a valid DHCP reply?

Regards

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B.Goode
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Joined: Mon Sep 01, 2014 4:03 pm
Location: UK

Re: Raspberry pi doesn't get ethernet internet from router

Sat Sep 14, 2019 6:19 pm

Is there a way to tell if the pi doesn't get a valid DHCP reply?

It won't get a valid IP network configuration.

You appear to be doing everything right. It should 'just work' without intervention 'out of the box.'

Options seem to be:
You are getting misleading results from one or more of the 'proven working' tests you have done;
There is some reason your network infrastructure is not working as expected: perhaps the pool of assignable addresses has been exhausted, or there is access filtering by Mac address;
or the Ethernet port on your RPi is faulty - perhaps as a side-effect of a power supply issue?

lorithai
Posts: 6
Joined: Tue Mar 01, 2016 7:02 pm

Re: Raspberry pi doesn't get ethernet internet from router

Sat Sep 14, 2019 6:47 pm

B.Goode wrote:
Sat Sep 14, 2019 6:19 pm
Is there a way to tell if the pi doesn't get a valid DHCP reply?

It won't get a valid IP network configuration.

You appear to be doing everything right. It should 'just work' without intervention 'out of the box.'

Options seem to be:
You are getting misleading results from one or more of the 'proven working' tests you have done;
There is some reason your network infrastructure is not working as expected: perhaps the pool of assignable addresses has been exhausted, or there is access filtering by Mac address;
or the Ethernet port on your RPi is faulty - perhaps as a side-effect of a power supply issue?
For the proven working tests i just connect my laptop to the router with the cables that i have, and it just works. I also connect the laptop to a second router that i have and that also works. By works, i mean i get internet access.

The router is set up with a dhcp server with the range 169.254.55.2-169.254.55.254 with the router having ip 169.254.55.1. mask is 255.255.255.0.

There is currently only one thing connected at a time to this router so address exhaustion is doubtful. There is also no form of mac address filtering.

I'll try some different power supplies to check that.

Regards

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B.Goode
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Joined: Mon Sep 01, 2014 4:03 pm
Location: UK

Re: Raspberry pi doesn't get ethernet internet from router

Sat Sep 14, 2019 8:08 pm

I am going to withdraw from the conversation at this point.

I have never encountered a network infrastructure built using RFC 3927 APIPA addresses - https://tools.ietf.org/html/rfc3927

I wonder if that might be confusing the IP network configuration used by Raspbian/Debian? Do you have any other Linux devices working on the network, or is this RPi the first?

There are a number of other volunteer helpers in these forums far more knowledgeable about this than I am, hopefully this thread will come to their attention.

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DougieLawson
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Re: Raspberry pi doesn't get ethernet internet from router

Sat Sep 14, 2019 8:36 pm

The router is badly configured. Using the 169.254.xxx.xxx link-local subnet isn't valid. Use one of the private, non-routable network blocks from 192.168.xxx.xxx/24, 172.[16-31].xxx.xxx/16 or 10.xxx.xxx.xxx/8 on the router.
Note: Having anything humorous in your signature is completely banned on this forum. Wear a tin-foil hat and you'll get a ban.

Any DMs sent on Twitter will be answered next month.

This is a doctor free zone.

lorithai
Posts: 6
Joined: Tue Mar 01, 2016 7:02 pm

Re: Raspberry pi doesn't get ethernet internet from router

Sun Sep 15, 2019 7:19 am

DougieLawson wrote:
Sat Sep 14, 2019 8:36 pm
The router is badly configured. Using the 169.254.xxx.xxx link-local subnet isn't valid. Use one of the private, non-routable network blocks from 192.168.xxx.xxx/24, 172.[16-31].xxx.xxx/16 or 10.xxx.xxx.xxx/8 on the router.
Ah, jeez, yeah, that was the issue. The routers i use were set up this way for reasons unknown to me and they worked fine with the raspberry pis at that time (using Jessie).

One of the PIs i have with jessie and also the other devices i have (laptops, pcs) work, but i guess they don't follow the protocols that strictly.

I appreciate the help B.Goode and DougieLawson.

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