Ygtjki

Everything was working fine up until today, I've been fiddling for hours trying to configure ethernet on my arch install with no luck. I run a dual boot system with windows and networking seems to be working fine there.

No matter what I tried every time I tried to ping an address I just got "network unreachable"

I tried booting from a live CD made using the same ISO that I used to make my install in the first place. That doesn't seem to want to connect either (although it worked fine when I used it to make my installation)

Following through the arch wiki I get the following outputs.

lspci -v

04:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 06)
...
Kernel driver in use: r8169
Kernel modules: r8169

dmesg | grep r8169

[ 4.489078] libphy: r8169: probed
[ 4.489584] r8169 0000:04:00.0 eth0: RTL8168evl/8111evl, 50:e5:49:44:08:b9, XID 2c900800, IRQ 34
[ 4.489586] r8169 0000:04:00.0 eth0: jumbo features [frames: 9200 bytes, tx checksumming: ko]
[ 4.493645] r8169 0000:04:00.0 enp4s0: renamed from eth0
[ 5.360274] RTL8211E Gigabit Ethernet r8169-400:00: attached PHY driver [RTL8211E Gigabit Ethernet] (mii_bus:phy_addr=r8169-400:00, irq=IGNORE)

From what I can gather this means the kernel driver has been loaded

ip link show dev enp4s0

2: enp4s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN mode DEFAULT group default qlen 1000 
link/ether 50:e5:49:44:08:b9 brd ff:ff:ff:ff:ff:ff

Interface seems to be up but when I run dhcpcd I get an error

sudo dhcpcd enp4s0

enp4s0: waiting for carrier
timed out
dhcpcd exited

I also tried using the example ethernet-dhcp and ethernet-static configs with netctl (changing eth0 to enp4s0 for each config) then enabling and starting them with "netctl enable ethernet-xxx" and "netctl start ethernet-xxxx". That didn't return any errors but I still get "network unreachable".

Interface is down and has no carrier. check cabling (NO-CARRIER and state DOWN show this).

what does ifconfig enp4s0 up say?

It turned out to be an issue with something in the bios that a recent failed overclock must have reverted.

I'm not exactly sure what the BIOS setting that was causing the issue was as I just reverted back to my preset but someone from this thread suggested to check the PXE setting.