Since I have installed Ubuntu 20.04 on my desktop PC, I keep experiencing a strange problem with wired network connectivity: sometimes, after the OS completes the boot process and I'm presented with the login screen, the network connection icon on the status bar doesn't switch to the "OK" status, remaining stucked to the "connecting" status (the same icon, but partially filled). After logging in, the network is unreachable.
I said "sometimes" because this issue doesn't show up at EVERY boot, but only from time to time, in a seemingly random way.
Since this issue is intermittent, I'd exclude hardware/driver-related problems; if I'd have to guess, I'd opt for an Ubuntu-related issue, but I don't even know how to start debugging this problem.
Running sudo lshw -C network yields this output:
*-network description: Ethernet interface product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:01:00.0 logical name: enp1s0 version: 15 serial: xxxxxx size: 1Gbit/s capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 duplex=full firmware=rtl8168h-2_0.0.2 02/26/15 latency=0 link=yes multicast=yes port=MII speed=1Gbit/s resources: irq:16 ioport:3000(size=256) memory:a1104000-a1104fff memory:a1100000-a1103fffThis is the ouput of sudo journalctl -b 0 -u NetworkManager for a BAD boot (i.e. when network connectivity fails to activate):
-- Logs begin at Tue 2020-12-01 15:28:02 CET, end at Sun 2020-12-06 15:16:00 CET. --
dic 01 18:26:16 elminster systemd[1]: Starting Network Manager...
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.2813] NetworkManager (version 1.22.10) is starting... (for the first time)
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.2813] Read config: /etc/NetworkManager/NetworkManager.conf (lib: 10-dns-resolved.conf, 20-connectivity-ubuntu.conf, no-mac-addr-change.conf) (run: 10-globally-managed-devices.conf) (etc: default-wifi-powersave-on.conf)
dic 01 18:26:16 elminster systemd[1]: Started Network Manager.
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.2836] bus-manager: acquired D-Bus service "org.freedesktop.NetworkManager"
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.2923] manager[0x55e3b0b54030]: monitoring kernel firmware directory '/lib/firmware'.
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.2923] monitoring ifupdown state file '/run/network/ifstate'.
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.3791] hostname: hostname: using hostnamed
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.3791] hostname: hostname changed from (none) to "elminster"
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.3793] dns-mgr[0x55e3b0b3e290]: init: dns=systemd-resolved rc-manager=symlink, plugin=systemd-resolved
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.3795] manager[0x55e3b0b54030]: rfkill: Wi-Fi hardware radio set enabled
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.3795] manager[0x55e3b0b54030]: rfkill: WWAN hardware radio set enabled
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.3877] Loaded device plugin: NMAtmManager (/usr/lib/x86_64-linux-gnu/NetworkManager/1.22.10/libnm-device-plugin-adsl.so)
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.3947] Loaded device plugin: NMTeamFactory (/usr/lib/x86_64-linux-gnu/NetworkManager/1.22.10/libnm-device-plugin-team.so)
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.3972] Loaded device plugin: NMWifiFactory (/usr/lib/x86_64-linux-gnu/NetworkManager/1.22.10/libnm-device-plugin-wifi.so)
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.4021] Loaded device plugin: NMWwanFactory (/usr/lib/x86_64-linux-gnu/NetworkManager/1.22.10/libnm-device-plugin-wwan.so)
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.4091] Loaded device plugin: NMBluezManager (/usr/lib/x86_64-linux-gnu/NetworkManager/1.22.10/libnm-device-plugin-bluetooth.so)
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.4093] manager: rfkill: Wi-Fi enabled by radio killswitch; enabled by state file
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.4094] manager: rfkill: WWAN enabled by radio killswitch; enabled by state file
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.4094] manager: Networking is enabled by state file
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.4095] dhcp-init: Using DHCP client 'internal'
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.4117] settings: Loaded settings plugin: ifupdown ("/usr/lib/x86_64-linux-gnu/NetworkManager/1.22.10/libnm-settings-plugin-ifupdown.so")
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.4118] settings: Loaded settings plugin: keyfile (internal)
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.4118] ifupdown: management mode: unmanaged
dic 01 18:26:16 elminster NetworkManager[1005]: <warn> [1606843576.4122] ifupdown: interfaces file /etc/network/interfaces doesn't exist
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.4141] device (lo): carrier: link connected
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.4142] manager: (lo): new Generic device (/org/freedesktop/NetworkManager/Devices/1)
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.4148] manager: (enp1s0): new Ethernet device (/org/freedesktop/NetworkManager/Devices/2)
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.4180] settings: (enp1s0): created default wired connection 'Wired connection 1'
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.4187] device (enp1s0): state change: unmanaged -> unavailable (reason 'managed', sys-iface-state: 'external')
dic 01 18:26:16 elminster NetworkManager[1005]: <warn> [1606843576.5374] Error: failed to open /run/network/ifstate
dic 01 18:26:16 elminster NetworkManager[1005]: <info> [1606843576.5442] modem-manager: ModemManager available
dic 01 18:26:20 elminster NetworkManager[1005]: <info> [1606843580.0982] device (enp1s0): carrier: link connected
dic 01 18:26:20 elminster NetworkManager[1005]: <info> [1606843580.0984] device (enp1s0): state change: unavailable -> disconnected (reason 'carrier-changed', sys-iface-state: 'managed')
dic 01 18:26:20 elminster NetworkManager[1005]: <info> [1606843580.0989] policy: auto-activating connection 'Wired connection 1' (60f5244b-484f-3471-bbc5-cea3a254d520)
dic 01 18:26:20 elminster NetworkManager[1005]: <info> [1606843580.0993] device (enp1s0): Activation: starting connection 'Wired connection 1' (60f5244b-484f-3471-bbc5-cea3a254d520)
dic 01 18:26:20 elminster NetworkManager[1005]: <info> [1606843580.0994] device (enp1s0): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
dic 01 18:26:20 elminster NetworkManager[1005]: <info> [1606843580.0996] manager: NetworkManager state is now CONNECTING
dic 01 18:26:20 elminster NetworkManager[1005]: <info> [1606843580.0997] device (enp1s0): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
dic 01 18:26:20 elminster NetworkManager[1005]: <info> [1606843580.1000] device (enp1s0): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
dic 01 18:26:20 elminster NetworkManager[1005]: <info> [1606843580.1002] dhcp4 (enp1s0): activation: beginning transaction (timeout in 45 seconds)
dic 01 18:26:32 elminster NetworkManager[1005]: <info> [1606843592.9532] agent-manager: agent[e115c8494fc78893,:1.72/ agent registered
dic 01 18:27:05 elminster NetworkManager[1005]: <warn> [1606843625.8067] dhcp4 (enp1s0): request timed out
dic 01 18:27:05 elminster NetworkManager[1005]: <info> [1606843625.8068] dhcp4 (enp1s0): state changed unknown -> timeout
dic 01 18:27:05 elminster NetworkManager[1005]: <info> [1606843625.8069] device (enp1s0): state change: ip-config -> failed (reason 'ip-config-unavailable', sys-iface-state: 'managed')
dic 01 18:27:05 elminster NetworkManager[1005]: <info> [1606843625.8079] manager: NetworkManager state is now CONNECTED_LOCAL
dic 01 18:27:05 elminster NetworkManager[1005]: <warn> [1606843625.8098] device (enp1s0): Activation: failed for connection 'Wired connection 1'
dic 01 18:27:05 elminster NetworkManager[1005]: <info> [1606843625.8103] device (enp1s0): state change: failed -> disconnected (reason 'none', sys-iface-state: 'managed')
dic 01 18:27:05 elminster NetworkManager[1005]: <info> [1606843625.8267] dhcp4 (enp1s0): canceled DHCP transaction
dic 01 18:27:05 elminster NetworkManager[1005]: <info> [1606843625.8267] dhcp4 (enp1s0): state changed timeout -> done
dic 01 18:27:05 elminster NetworkManager[1005]: <info> [1606843625.8293] policy: auto-activating connection 'Wired connection 1' (60f5244b-484f-3471-bbc5-cea3a254d520)
dic 01 18:27:05 elminster NetworkManager[1005]: <info> [1606843625.8298] device (enp1s0): Activation: starting connection 'Wired connection 1' (60f5244b-484f-3471-bbc5-cea3a254d520)
dic 01 18:27:05 elminster NetworkManager[1005]: <info> [1606843625.8299] device (enp1s0): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
dic 01 18:27:05 elminster NetworkManager[1005]: <info> [1606843625.8301] manager: NetworkManager state is now CONNECTING
dic 01 18:27:05 elminster NetworkManager[1005]: <info> [1606843625.8303] device (enp1s0): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
dic 01 18:27:05 elminster NetworkManager[1005]: <info> [1606843625.8307] device (enp1s0): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
dic 01 18:27:05 elminster NetworkManager[1005]: <info> [1606843625.8309] dhcp4 (enp1s0): activation: beginning transaction (timeout in 45 seconds)
dic 01 18:27:50 elminster NetworkManager[1005]: <warn> [1606843670.8087] dhcp4 (enp1s0): request timed out
dic 01 18:27:50 elminster NetworkManager[1005]: <info> [1606843670.8088] dhcp4 (enp1s0): state changed unknown -> timeout
dic 01 18:27:50 elminster NetworkManager[1005]: <info> [1606843670.8089] device (enp1s0): state change: ip-config -> failed (reason 'ip-config-unavailable', sys-iface-state: 'managed')
dic 01 18:27:50 elminster NetworkManager[1005]: <info> [1606843670.8098] manager: NetworkManager state is now CONNECTED_LOCAL
dic 01 18:27:50 elminster NetworkManager[1005]: <warn> [1606843670.8115] device (enp1s0): Activation: failed for connection 'Wired connection 1'
dic 01 18:27:50 elminster NetworkManager[1005]: <info> [1606843670.8120] device (enp1s0): state change: failed -> disconnected (reason 'none', sys-iface-state: 'managed')
dic 01 18:27:50 elminster NetworkManager[1005]: <info> [1606843670.8427] dhcp4 (enp1s0): canceled DHCP transaction
dic 01 18:27:50 elminster NetworkManager[1005]: <info> [1606843670.8427] dhcp4 (enp1s0): state changed timeout -> done
dic 01 18:27:50 elminster NetworkManager[1005]: <info> [1606843670.8467] policy: auto-activating connection 'Wired connection 1' (60f5244b-484f-3471-bbc5-cea3a254d520)
dic 01 18:27:50 elminster NetworkManager[1005]: <info> [1606843670.8474] device (enp1s0): Activation: starting connection 'Wired connection 1' (60f5244b-484f-3471-bbc5-cea3a254d520)
dic 01 18:27:50 elminster NetworkManager[1005]: <info> [1606843670.8475] device (enp1s0): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
dic 01 18:27:50 elminster NetworkManager[1005]: <info> [1606843670.8477] manager: NetworkManager state is now CONNECTING
dic 01 18:27:50 elminster NetworkManager[1005]: <info> [1606843670.8479] device (enp1s0): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
dic 01 18:27:50 elminster NetworkManager[1005]: <info> [1606843670.8483] device (enp1s0): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
dic 01 18:27:50 elminster NetworkManager[1005]: <info> [1606843670.8485] dhcp4 (enp1s0): activation: beginning transaction (timeout in 45 seconds)
dic 01 18:28:35 elminster NetworkManager[1005]: <warn> [1606843715.8092] dhcp4 (enp1s0): request timed out
dic 01 18:28:35 elminster NetworkManager[1005]: <info> [1606843715.8092] dhcp4 (enp1s0): state changed unknown -> timeout
dic 01 18:28:35 elminster NetworkManager[1005]: <info> [1606843715.8094] device (enp1s0): state change: ip-config -> failed (reason 'ip-config-unavailable', sys-iface-state: 'managed')
dic 01 18:28:35 elminster NetworkManager[1005]: <info> [1606843715.8104] manager: NetworkManager state is now CONNECTED_LOCAL
dic 01 18:28:35 elminster NetworkManager[1005]: <warn> [1606843715.8122] device (enp1s0): Activation: failed for connection 'Wired connection 1'
dic 01 18:28:35 elminster NetworkManager[1005]: <info> [1606843715.8128] device (enp1s0): state change: failed -> disconnected (reason 'none', sys-iface-state: 'managed')
dic 01 18:28:35 elminster NetworkManager[1005]: <info> [1606843715.8306] dhcp4 (enp1s0): canceled DHCP transaction
dic 01 18:28:35 elminster NetworkManager[1005]: <info> [1606843715.8307] dhcp4 (enp1s0): state changed timeout -> done
dic 01 18:28:35 elminster NetworkManager[1005]: <info> [1606843715.8332] policy: auto-activating connection 'Wired connection 1' (60f5244b-484f-3471-bbc5-cea3a254d520)
dic 01 18:28:35 elminster NetworkManager[1005]: <info> [1606843715.8338] device (enp1s0): Activation: starting connection 'Wired connection 1' (60f5244b-484f-3471-bbc5-cea3a254d520)
dic 01 18:28:35 elminster NetworkManager[1005]: <info> [1606843715.8339] device (enp1s0): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')Any ideas?
Thanks in advance to whoever will answer.
2 Reset to default
