Internet Connection

Question

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

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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.

Answer 1

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.

Answer 2

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