I have the exact same problem using 21.04. After resume it says something about the network cable being unplugged in the settings menu under network wired. I have found rebooting is the fastest way (only way that I know that works) to get back running. My work around is to not suspend. Configuration information:
lshw -C network outpu (with the network running) *-network description: Ethernet interface product: Killer E2400 Gigabit Ethernet Controller vendor: Qualcomm Atheros physical id: 0 bus info: pci@0000:04:00.0 logical name: enp4s0 version: 10 serial: 00:4e:01:ac:76:26 size: 1Gbit/s capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: pm pciexpress msi msix bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=alx driverversion=5.11.0-25-generic duplex=full ip=192.168.1.25 latency=0 link=yes multicast=yes port=twisted pair speed=1Gbit/s resources: irq:19 memory:ec500000-ec53ffff ioport:d000(size=128) -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1931301 Title: NIC unavailable after suspend to RAM Status in linux package in Ubuntu: Confirmed Status in linux source package in Hirsute: Confirmed Bug description: [SRU Justification] [Impact] The network card will be unavailable after system resume if the interface is not UP before suspend. [Fix] It's because we added the WOL support for this driver. The driver with WoL feature does detach the network interface even the interface is DOWN. However, it doesn't attach the network interface back on resume if it was DOWN. That's why it's unavailable after resume. Fix this by correctly netif_device_attach according to the interface status. [Test Case] 1. Plug the ethernet cable to the Atheros E220x ethernet adapter 2. Suspend the system and check if the ethernet interface available after resume 3. Unplug the ethernet cable 4. Suspend the system and check if the ethernet interface available after resume [Regression Potential] Low. The driver code would be identical to working Groovy version after fix. ========== Original Bug Description ========== Upgraded to 21.04 (hirsute) and now the network card is unavailable after suspend to RAM (sleep state S3). It worked flawlessly up until 20.10. My workaround for now is unloading and reloading the kernel module, but that won't work for normal users, hence this report. NIC in its unavailable state: 2: enp4s0: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN group default qlen 1000 link/ether d0:50:99:27:02:11 brd ff:ff:ff:ff:ff:ff NIC (from lspci): 04:00.0 Ethernet controller: Qualcomm Atheros Killer E220x Gigabit Ethernet Controller (rev 10) Trying to ifconfig it down/up results in: SIOCSIFFLAGS: No such device journalctl shows (right after recovering from suspend): NetworkManager[1911]: <info> [1623181236.9371] manager: sleep: wake requested (sleeping: yes enabled: yes) NetworkManager[1911]: <info> [1623181236.9372] device (enp4s0): state change: unmanaged -> unavailable (reason 'managed', sys-iface-state: 'external') NetworkManager[1911]: <info> [1623181236.9382] manager: NetworkManager state is now CONNECTED_LOCAL ProblemType: Bug DistroRelease: Ubuntu 21.04 Package: network-manager 1.30.0-1ubuntu3 ProcVersionSignature: Ubuntu 5.11.0-18.19-generic 5.11.17 Uname: Linux 5.11.0-18-generic x86_64 ApportVersion: 2.20.11-0ubuntu65.1 Architecture: amd64 CasperMD5CheckResult: unknown Date: Tue Jun 8 21:59:15 2021 IfupdownConfig: # interfaces(5) file used by ifup(8) and ifdown(8) auto lo iface lo inet loopback InstallationDate: Installed on 2016-08-25 (1748 days ago) InstallationMedia: Ubuntu-MATE 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719) RfKill: SourcePackage: network-manager UpgradeStatus: Upgraded to hirsute on 2021-06-04 (4 days ago) nmcli-nm: RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN running 1.30.0 connected started full enabled enabled enabled enabled enabled To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1931301/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp