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I'm a newbie to the Raspberry world. Just bought a Raspberry 4 model B and having problems connecting it to the internet.

I am using an ethernet cable but the device will not connect to the internet. The network lights (next to the connector) light up but it won't access the internet. When I connect the same ethernet cable to my laptop, my laptop can connect to the internet fine.

Not sure how to proceed with the troubleshooting, will appreciate your advice.

Thanks, Avi

Hi, I realize my question is not clear, here is some additional information which might help. Thanks.

The Ethernet cable is connected to a Cisco SG110-16 switch, which is connected to an Apple AirPort Extreme router. I do not know if it has MAC filtering or how to check this. (I sent a question for the switch installer, waiting for his reply).

The lights next to the connector show a flashing green and a solid yellow.

I can use terminal with commands on the Raspberry, however have no way to copy and paste the results (many lines..) to the laptop from which I’m using to write this.

The GUI in the upper right corner shows the WiFi icon, it recognizes the network, asked for and received the correct password, but is not connecting either. The WiFi icon is not solid blue, but instead continuous “growing arches”, if it means anything.

ok, made some progress... I entered the IP, Router and DNS values (as shown in the router) into the Raspberry network preferences window. This brought up the blue arrows icon on the GUI, and when hovering the mouse over it the following shows: "eth0: Link is up, configuring"

Still, no internet connection.

AviHarari
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  • You have provided no information. What is the Ethernet cable connected to? what does the GUI networking icon show? What is the output of ip a? What colour sre the Ethernet LEDs? – Milliways Feb 29 '20 at 08:52
  • The Ethernet cable is connected to a switch which is connected to an Apple AirPort Extreme router. – AviHarari Feb 29 '20 at 10:10
  • The lights at the connector are flashing green and solid yellow. The GUI shows the WiFi icon, but doesn't connect either. – AviHarari Feb 29 '20 at 10:11
  • Sorry. It is a Cisco SG110-16 switch, supports Gigabit Ethernet. Regarding the ip a command, I get a long list of rows, anything in particular to look for? (I can't copy and paste between the MacBook and the Raspberry) – AviHarari Feb 29 '20 at 10:24
  • Does your Cisco switch have MAC filtering enabled? Have you updated that for the RPi MAC address? – Dougie Feb 29 '20 at 10:42
  • It is difficult to help without meaningful diagnostics. You should check if an IP address has been allocated, and report this. ethtool eth0 will report Ethernet status and speed, although I don't know if this is installed by default. Many people who have trouble with Ethernet on Pi3B+ & Pi4 are not using proper 8 wire CAT5 cables, which are necessary for Gigabit Ethernet. You should be able to check on your router (from the Mac) if the Pi is connected. PS DO NOT post in Comments, edit your Question with detail. – Milliways Feb 29 '20 at 10:50
  • I suggest you unplug the Ethernet cable and connect WiFi See How to set up networking/WiFi – Milliways Feb 29 '20 at 11:17
  • @Milliways ethtool appears to be installed by default on Raspbian Buster. – Bob Brown Feb 29 '20 at 15:30
  • Ping the gateway of the network. If you don't know the gateway's IP address, check it out by sudo route -n (note that it will work if you set the eth0 as DHCP Client mode and haven't configured a static IP address). If you find the gateway on the raspberry pi and can ping it but still no internet (8.8.8.8 can be pinged), it's a problem on your network instructor which can be MAC filtering, etc. – M. Rostami Feb 29 '20 at 18:27

2 Answers2

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As you are a newbie and it is difficult to provide the required information if you don't know much about the problem, I suggest the following steps. Note that I assume that you have monitor+keyboard on your Pi and commandline access as root.

  1. Get the information that is needed from your network. Does it do DHCP? Do you need to fill-in a specific IP address, netmask and gateway?
  2. tail -f /var/log/messages in a console window
  3. Connect to the switch with Ethernet. If your network uses DHCP, you should see some messages that dhcpcd is doing something.
  4. If you need to set IP address yourself, do ifconfig eth0 10.1.1.100 netmask 255.255.255.0 upand route add default gw 10.1.1.1; replace the IP addresses and netmask with what you have got from your network.
  5. Ping your default gateway( ping -c2 10.1.1.1). Does it respond? If not: try arp -a: is your default gateway there? If not: you have a connectivity problem. That may be a faulty network cable, a port on the switch that is shut or something else.
  6. If you use DHCP and have a valid IP address/default gateway, then you should have a connection to the internal network.
  7. If you have a connection to the internal network, that does not automatically mean that you can connect to the Internet. In a normal SOHO situation though, it would give you access.
Ljm Dullaart
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  • Thank you for the reply. I do understand the difficulty in providing help when the knowledge difference is big, and I appreciate the effort. I spent many hours of trying to troubleshoot this problem, including having a pro guide me over the phone, alas no connection was made. I finally decided to try with a new raspian OS, so I formatted the memory card and installed a fresh copy. Not sure why but this solved the issue, now both Ethernet and WiFi are working. I move on... – AviHarari Mar 01 '20 at 19:05
  • @AviHarari Please create an answer for the solution of your problem and accept it with a click on the tick on its left side after two days. Only accepting an answer will finish the question and it will not pop up again and again for years. – Ingo Mar 03 '20 at 20:23
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I finally decided to try with a new raspian OS, so I formatted the memory card and installed a fresh copy. Not sure why but this solved the issue, now both Ethernet and WiFi are working

AviHarari
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  • Please accept your own answer with a click on the tick on its left side. Only this will finish the question and it will not pop up again year for year. – Ingo Mar 09 '20 at 10:32