Raspberry Pi 4 - Network Issues

Order your own Raspberry Pi 4

So.. a new Raspberry PI!

Bigger, stronger, faster right? Well, sort of. All of the other pi's I have tested are pretty much plug and play....Plug in all the stuff in the right ports, turn it on and play.

The Problem

On first fire up of the new Pi4 all seemed to be grand except for one thing: No Network. Now without a network connection the pi is pretty much useless. Not so much that you cannot connect to anything to play around, you can't connect to anything to update it to fix problems. This meant that it was back and forth between my cell phone, my PC and the pi4. HORRIBLE! Granted, it is all new, the hardware and the OS so problems can be expected right off the bat.

The Fix

Update 2019Dec07 sudo nano /etc/dhpcd.conf Added the line ipv4only after hostname Try sudo dhcpcd --reconfig I also found that there was a wpa_supplicant in the /boot directory. I removed it and then it booted with wifi successfully. You may want to still follow the steps below to insure ipv6 is turned off. more... After about 4 hours of off and on troubleshooting on that first unit, re-imaging, playing with dhcp, wifi and even hard wiring it to the network.. it turns out that IPV6 was the culprit. I found this when by chance I ran the command: sudo dhcpcd eth0 It promptly returned a buffer overflow error. Finally, I was on to something. I went into the /etc/modprobe.d/ipv6.conf file and un-remarked the line that says "alias ipv6 off" After some additional reading I also went into the /boot/cmdline.txt and added ipv6.disable=1. sudo nano /boot/cmdline.txt Add the line ipv6.disable=1 Reboot the pi. At that point, both the wlan0 for wifi and the eth0 for the hard wired connection pulled an IP address from DHCP. Once I had connectivity I ran sudo apt-get update and sudo apt-get upgrade hoping that something in an update will fix it and I can turn IPV6 back on. It turns out that after doing the updates turning on IP V6 simply broke network connectivity so I have turned it back off until I can research it further. Funny thing was that reading through some blogs one of the comments were "you should not turn off IPV6 but instead try to find out what is wrong and leave it on" because it is directional. I am now thinking that if it is actually causing buffer overruns, it might be better to wait until the 'raspi-nix folks fix the problem first. Here is a video I put up on YouTube about it: View on YouTube This also resolved my wifi boot problems on a raspberry pi 3, buster and no wifi network. After countless hours, the fix ended up being: If ipv6.conf does not exist, create a new one, I had to. sudo nano /etc/modprobe.d/ipv6.conf Enter the following text alias net-pf-10 off alias ipv6 off blacklist ipv6 After I did this and rebooted wifi was working and wlan0 now pulled an ip address. It is almost like once it wants to go IPV6, IPV4 simply does not end up being a selection, even if it does not seem to be supported on the local network, or via wifi minimally. Like so many other nix things, after two days of messing around, it is hard to say what actually fixed the problem though. There was some playing with wpa_supplicant, it's conf file and running it directly. This seemed somewhat of a necessity because at one point wan0 disappeared completely. If I decide to wipe and create a new build, I will do a step by step fix. IMO, a simply wifi pi should not entail this great of an effort.