Ethernet stopped working suddenly yesterday, possible DHCP problem?
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Ethernet stopped working suddenly yesterday, possible DHCP problem?
(I'm running Fedora 35)
So, I was not doing anything in particular yesterday afternoon and all of a sudden my ethernet stopped working. I figured it might've been some sort of bug so I just shut off my PC and hoped it would be fixed today, but no.
After a lot of digging around it seems to be related to DHCP, it keeps trying to get an IP but fails and repeats this indefinitely. I've never had this problem before and it came all of a sudden.
Here's a bit from journalctl:
Journalctl:
Code:
Jan 09 16:55:25 fedora kernel: r8169 0000:22:00.0 enp34s0: renamed from eth0 Jan 09 15:55:30 fedora NetworkManager[947]: <info> [1641740130.4925] manager: (enp34s0): new Ethernet device (/org/freedesktop/NetworkManager/Devices/2) Jan 09 15:55:30 fedora NetworkManager[947]: <info> [1641740130.4928] device (enp34s0): state change: unmanaged -> unavailable (reason 'managed', sys-iface-state: 'external') Jan 09 15:55:30 fedora kernel: r8169 0000:22:00.0 enp34s0: Link is Down Jan 09 15:55:32 fedora NetworkManager[947]: <info> [1641740132.1991] device (enp34s0): carrier: link connected Jan 09 15:55:32 fedora NetworkManager[947]: <info> [1641740132.1993] device (enp34s0): state change: unavailable -> disconnected (reason 'carrier-changed', sys-iface-state: 'managed') Jan 09 15:55:32 fedora kernel: r8169 0000:22:00.0 enp34s0: Link is Up - 100Mbps/Full - flow control rx/tx Jan 09 15:55:32 fedora kernel: IPv6: ADDRCONF(NETDEV_CHANGE): enp34s0: link becomes ready Jan 09 15:55:32 fedora NetworkManager[947]: <info> [1641740132.2004] device (enp34s0): Activation: starting connection 'Wired connection 1' (c67eb488-01f9-3043-a281-94e2c0447efc) Jan 09 15:55:32 fedora NetworkManager[947]: <info> [1641740132.2005] device (enp34s0): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed') Jan 09 15:55:32 fedora NetworkManager[947]: <info> [1641740132.2009] device (enp34s0): state change: prepare -> config (reason 'none', sys-iface-state: 'managed') Jan 09 15:55:32 fedora NetworkManager[947]: <info> [1641740132.2293] device (enp34s0): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed') Jan 09 15:55:32 fedora NetworkManager[947]: <info> [1641740132.2296] dhcp4 (enp34s0): activation: beginning transaction (timeout in 45 seconds) Jan 09 15:55:32 fedora avahi-daemon[840]: Joining mDNS multicast group on interface enp34s0.IPv6 with address (censored). Jan 09 15:55:32 fedora avahi-daemon[840]: New relevant interface enp34s0.IPv6 for mDNS. Jan 09 15:55:32 fedora avahi-daemon[840]: Registering new address record for fe80::386:14c4:4ef2:d2cb on enp34s0.. Jan 09 15:56:17 fedora NetworkManager[947]: <warn> [1641740177.0622] dhcp4 (enp34s0): request timed out Jan 09 15:56:17 fedora NetworkManager[947]: <info> [1641740177.0622] dhcp4 (enp34s0): state changed unknown -> timeout Jan 09 15:56:17 fedora NetworkManager[947]: <info> [1641740177.0623] device (enp34s0): state change: ip-config -> failed (reason 'ip-config-unavailable', sys-iface-state: 'managed') Jan 09 15:56:17 fedora NetworkManager[947]: <warn> [1641740177.0629] device (enp34s0): Activation: failed for connection 'Wired connection 1' Jan 09 15:56:17 fedora NetworkManager[947]: <info> [1641740177.0631] device (enp34s0): state change: failed -> disconnected (reason 'none', sys-iface-state: 'managed') Jan 09 15:56:17 fedora avahi-daemon[840]: Withdrawing address record for fe80::386:14c4:4ef2:d2cb on enp34s0. Jan 09 15:56:17 fedora avahi-daemon[840]: Leaving mDNS multicast group on interface enp34s0.IPv6 with address (censored). Jan 09 15:56:17 fedora avahi-daemon[840]: Interface enp34s0.IPv6 no longer relevant for mDNS. Jan 09 15:56:17 fedora NetworkManager[947]: <info> [1641740177.0756] dhcp4 (enp34s0): canceled DHCP transaction Jan 09 15:56:17 fedora NetworkManager[947]: <info> [1641740177.0756] dhcp4 (enp34s0): state changed timeout -> terminated Jan 09 15:56:17 fedora NetworkManager[947]: <info> [1641740177.0770] device (enp34s0): Activation: starting connection 'Wired connection 1' (c67eb488-01f9-3043-a281-94e2c0447efc) Jan 09 15:56:17 fedora NetworkManager[947]: <info> [1641740177.0771] device (enp34s0): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed') Jan 09 15:56:17 fedora NetworkManager[947]: <info> [1641740177.0774] device (enp34s0): state change: prepare -> config (reason 'none', sys-iface-state: 'managed') Jan 09 15:56:17 fedora NetworkManager[947]: <info> [1641740177.0821] device (enp34s0): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed') Jan 09 15:56:17 fedora NetworkManager[947]: <info> [1641740177.0823] dhcp4 (enp34s0): activation: beginning transaction (timeout in 45 seconds) Jan 09 15:56:17 fedora avahi-daemon[840]: Joining mDNS multicast group on interface enp34s0.IPv6 with address (censored). Jan 09 15:56:17 fedora avahi-daemon[840]: New relevant interface enp34s0.IPv6 for mDNS. Jan 09 15:56:17 fedora avahi-daemon[840]: Registering new address record for (censored) on enp34s0.. Jan 09 15:56:26 fedora NetworkManager[947]: <info> [1641740186.2964] dhcp6 (enp34s0): activation: beginning transaction (timeout in 45 seconds) Jan 09 15:56:26 fedora avahi-daemon[840]: Leaving mDNS multicast group on interface enp34s0.IPv6 with address (censored). Jan 09 15:56:26 fedora avahi-daemon[840]: Joining mDNS multicast group on interface enp34s0.IPv6 with address (censored). Jan 09 15:56:26 fedora avahi-daemon[840]: Registering new address record for (censored) on enp34s0.*. Jan 09 15:56:26 fedora avahi-daemon[840]: Withdrawing address record for (censoredb on enp34s0. Jan 09 15:57:02 fedora NetworkManager[947]: <warn> [1641740222.0526] dhcp4 (enp34s0): request timed out Jan 09 15:57:02 fedora NetworkManager[947]: <info> [1641740222.0526] dhcp4 (enp34s0): state changed unknown -> timeout Jan 09 15:57:11 fedora NetworkManager[947]: <warn> [1641740231.0546] dhcp6 (enp34s0): request timed out Jan 09 15:57:11 fedora NetworkManager[947]: <info> [1641740231.0546] dhcp6 (enp34s0): state changed unknown -> timeout Jan 09 15:57:11 fedora NetworkManager[947]: <info> [1641740231.0547] dhcp6 (enp34s0): canceled DHCP transaction Jan 09 15:57:11 fedora NetworkManager[947]: <info> [1641740231.0547] dhcp6 (enp34s0): state changed timeout -> terminated Jan 09 15:57:11 fedora NetworkManager[947]: <info> [1641740231.0553] device (enp34s0): state change: ip-config -> ip-check (reason 'none', sys-iface-state: 'managed') Jan 09 15:57:11 fedora NetworkManager[947]: <info> [1641740231.0646] device (enp34s0): state change: ip-check -> secondaries (reason 'none', sys-iface-state: 'managed') Jan 09 15:57:11 fedora NetworkManager[947]: <info> [1641740231.0647] device (enp34s0): state change: secondaries -> activated (reason 'none', sys-iface-state: 'managed') Jan 09 15:57:11 fedora NetworkManager[947]: <info> [1641740231.0656] policy: set 'Wired connection 1' (enp34s0) as default for IPv6 routing and DNS Jan 09 15:57:11 fedora NetworkManager[947]: <info> [1641740231.0661] device (enp34s0): Activation: successful, device activated. Jan 09 15:57:11 fedora systemd-resolved[820]: enp34s0: Bus client set default route setting: yes Jan 09 15:57:11 fedora systemd-resolved[820]: enp34s0: Bus client set DNS server list to: (censored), (censored), (censored)
It also seems that I have an IPv6 address, but not an IPv4 one.
Pinging to localhost works, the interface is listed, but I can't ping to public IP addresses or other IP addresses in my network (except for one which I forgot), and I also can't see a routing table show up when I run
I just had a switch fail a few weeks ago and I've had network adapters that appear to work from the software side but not the physical end.
How is your PC / network physically wired?
Do other wired devices work as expected?
Make sure the network adapter has link lights and match the expected network speed i.e 100/1000 etc. on both ends. Try switching ports on the router if available.
Frankly I'm not sure, I didn't build my own PC nor connected the peripherals. But from what I can tell, the backside of the PC has an Ethernet cable connected to it, which is connected to a small white box (I think this is the switch?), which in return has a cable going down a hole in the wall, which I think is connected to the router ultimately (I hope it's not a hardware issue at least, this setup is a pain to replace).
The only other wired device is another PC and it works fine. On the wireless end, my phone and tablet can use Wi-Fi just fine.
I have a few reasons why I think the hardware still works though, but also one why it might not:
+ I can ping to localhost and one other public IP in the network just fine (forgot which IP exactly but IIRC it started with 10).
+ The lights on the switch are still on.
+ The light on my PC's ethernet port is also on.
- I can't get internet access either on a Fedora live USB.
Oh, and wait: I changed the rightmost cable in the switch (there are two of them, I changed the bigger one first and that didn't help, then I switched the small one to the right) and now my internet works again! Thank you so much!
Could you explain what this means, though? I figure one of the ports is broken, but I'm not sure.
Pinging localhost is strictly software and does not actually use hardware. If you pinged the private ip address ( I assume it was the 10.. number) of the computer itself does not either.
The port could be bad or just not negotiating correctly. You could switch it back and see if it works again.
Distribution: Ubuntu based stuff for the most part
Posts: 1,175
Rep:
Scrolling through your error log, your system is not finding anything to respond to it's DHCP request. It seems to be reporting no cable detected. Your wireless does nto seem to be configured, so maybe give that a try if you are sure the cable into the computer and the router is good.
From what I remember of IPv6, it self generates an address, so having one does not mean your network is up.
First, try pinging the router's ip address. If that's successful, your computer is communicating to the router. If it's not successful, check all your connections, try resetting the cable(s). If you have a cable tester, it might be a good idea to test the cable(s) with it.
TIf you are able to ping your router, then try pinging 8.8.8.8 (that's a Google ip). If that works, try pinging google.com. If that doesn't work and the pinging 8.8.8.8 did, you likely have a DNS problem.
You can also use the traceroute command to find out exactly where along the way the connection is failing. See man traceroute for more.
Oh, and wait: I changed the rightmost cable in the switch (there are two of them, I changed the bigger one first and that didn't help, then I switched the small one to the right) and now my internet works again! Thank you so much!
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