带有 Bullseye 的 Raspberry Pi 3B+ 根本没有 eth0 接口

Question

I'm trying to connect my Raspberry Pi 3B+ to my network. But neither do the LAN-LEDs light up nor does the Pi even know what eth0 is. I also have no en<x><MAC>.

ifconfig outputs the following (ifconfig -a does the same):

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
    inet 127.0.0.1 netmask 255.0.0.0
    inet6 ::1 prefixlen 128 scopeid 0x10<host>
    loop txqueuelen 1000 (Local Loopback)
    RX packets 10 bytes 1564 (1.5 KiB)
    RX errors 0 dropped 0 overruns 0 frame 0
    TX packets 10 bytes 1564 (1.5 KiB)
    TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

wlan0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
    ether MY-MAC-ADDRESS txqueuelen 1000 (Ethernet)
    RX packets 0 bytes 0 (0.0 B)
    RX errors 0 dropped 0 overruns 0 frame 0
    TX packets 0 bytes 0 (0.0 B)
    TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

/etc/network/interfaces is as follows:

# interfaces(5) file used by ifup(8) and ifdown(8)
# Include files from /etc/network/interfaces.d:
source /etc/network/interfaces.d/*

/etc/network/interfaces.d/ is empty.

Like I said, it doesn't know what eth0 is at all:

~$ ifup eth0
ifup: unknown interface eth0
~$ sudo dhclient eth0
Cannot find device "eth0"

The network cable works, tested it on other PCs and tried many different ones...

Answer 1

I believe there was a bug introduced in Bulleye.

If /boot/cmdline.txt does not have "net.ifnames=0", then add that to the end of the root= line. Then reboot.