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All of a sudden my Ubuntu 20.04 stopped renewing dhcp leases. My ethernet card has been assigned a fixed IP, but it needs to renew the lease every 12 hours. It does not. I need to unplug and re-plug the ethernet cable to be back on-line.

I have found plenty of unanswered questions here, so I think it is quite a hard issue, and found this discussion about an old bug: https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/1551351

However, I am not a system administrator so, basically, I do not know what to check and look for.

Is there anyone who can give me some suggestions besides renewing the lease every once in a while via command line?

In the logs:

sudo journalctl  -b 0 -u NetworkManager

as suggested in the comments, I see this Mar 08 23:44:58 pc-linux NetworkManager[1047]: [1646779498.8261] dhcp4 (enp6s0): error -113 dispatching events every time the DHCP lease should be renewed:

Mar 08 22:53:37 pc-linux NetworkManager[1047]: <info>  [1646776417.5168] dhcp6 (enp6s0): state changed bound -> bound
Mar 08 23:44:58 pc-linux NetworkManager[1047]: <error> [1646779498.8261] dhcp4 (enp6s0): error -113 dispatching events
Mar 08 23:44:58 pc-linux NetworkManager[1047]: <info>  [1646779498.8262] dhcp4 (enp6s0): state changed bound -> fail
Mar 08 23:44:58 pc-linux NetworkManager[1047]: <info>  [1646779498.8263] device (enp6s0): DHCPv4: trying to acquire a new lease within 90 seconds
Mar 08 23:46:28 pc-linux NetworkManager[1047]: <info>  [1646779588.9964] device (enp6s0): DHCPv4: grace period expired

I did not use the PC on the 9th of March.

On the 10th of March in the morning at 9:00 when I unplugged/plugged the network cable:

Mar 10 08:58:29 pc-linux NetworkManager[1047]: <info>  [1646899109.1535] agent-manager: agent[5214bc57140bb9cb,:1.84/org.gnome.Shell.NetworkAgent/1000]: agent registered
Mar 10 09:00:31 pc-linux NetworkManager[1047]: <info>  [1646899231.0908] device (enp6s0): carrier: link connected
Mar 10 09:00:31 pc-linux NetworkManager[1047]: <info>  [1646899231.0911] device (enp6s0): DHCPv4 lease renewal requested
Mar 10 09:00:31 pc-linux NetworkManager[1047]: <info>  [1646899231.0912] dhcp4 (enp6s0): canceled DHCP transaction
Mar 10 09:00:31 pc-linux NetworkManager[1047]: <info>  [1646899231.0912] dhcp4 (enp6s0): canceled DHCP transaction
Mar 10 09:00:31 pc-linux NetworkManager[1047]: <info>  [1646899231.0912] dhcp4 (enp6s0): state changed fail -> done
Mar 10 09:00:31 pc-linux NetworkManager[1047]: <info>  [1646899231.0935] dhcp4 (enp6s0): activation: beginning transaction (timeout in 45 seconds)

Yesterday at 21:00, when the lease should have been renewed:

ar 10 21:00:33 pc-linux NetworkManager[1047]: <error> [1646942433.1181] dhcp4 (enp6s0): error -113 dispatching events
Mar 10 21:00:33 pc-linux NetworkManager[1047]: <info>  [1646942433.1182] dhcp4 (enp6s0): state changed bound -> fail
Mar 10 21:00:33 pc-linux NetworkManager[1047]: <info>  [1646942433.1182] device (enp6s0): DHCPv4: trying to acquire a new lease within 90 seconds
Mar 10 21:02:02 pc-linux NetworkManager[1047]: <info>  [1646942522.9984] device (enp6s0): DHCPv4: grace period expired

only after a while:

Mar 10 22:23:16 pc-linux NetworkManager[1047]: <info>  [1646947396.9413] manager: NetworkManager state is now CONNECTED_SITE
Mar 10 22:23:17 pc-linux NetworkManager[1047]: <info>  [1646947397.1908] manager: NetworkManager state is now CONNECTED_GLOBAL
Mar 10 22:53:36 pc-linux NetworkManager[1047]: <info>  [1646949216.9407] manager: NetworkManager state is now CONNECTED_SITE
Mar 10 22:53:37 pc-linux NetworkManager[1047]: <info>  [1646949217.2368] manager: NetworkManager state is now CONNECTED_GLOBAL

The only warning messages I see are:

Mar 08 11:44:52 pc-linux NetworkManager[1047]: <warn>  [1646736292.8205] ifupdown: interfaces file /etc/network/interfaces doesn't exist
Mar 08 11:44:53 pc-linux NetworkManager[1047]: <warn>  [1646736293.1600] Error: failed to open /run/network/ifstate

This morning the DHCP was not renewed while editing this message at 9:00: right now I am disconnected and the logs just say:

Mar 11 08:56:57 pc-linux NetworkManager[1047]: <info>  [1646985417.5167] dhcp6 (enp6s0): option dhcp6_domain_search  => '#DOMAIN#'
Mar 11 08:56:57 pc-linux NetworkManager[1047]: <info>  [1646985417.5168] dhcp6 (enp6s0): option dhcp6_name_servers   => '#MAC1# #MAC2#'
Mar 11 08:56:57 pc-linux NetworkManager[1047]: <info>  [1646985417.5168] dhcp6 (enp6s0): option ip6_address          => '#MAC#'
Mar 11 08:56:57 pc-linux NetworkManager[1047]: <info>  [1646985417.5169] dhcp6 (enp6s0): state changed bound -> bound
Mar 11 09:02:26 pc-linux NetworkManager[1047]: <info>  [1646985746.9424] manager: NetworkManager state is now CONNECTED_SITE
lines 516-570/570 (END)

It is strange: I cannot visit any website. The error message is

https://www.amazon.it/ is unreachable.
ERR_ADDRESS_UNREACHABLE

the same for every other website and domain:

https://www.bbc.co.uk/ is unreachable.
ERR_ADDRESS_UNREACHABLE

Strangely, I can make web searches on Google (my DNS servers are provided by my employer and I do not use the google ones). I am not able to interpret this behaviour.

After unplugging/plugging the network cable:

Mar 11 09:11:34 pc-linux NetworkManager[1047]: <info>  [1646986294.6023] device (enp6s0): carrier: link connected
Mar 11 09:11:34 pc-linux NetworkManager[1047]: <info>  [1646986294.6026] device (enp6s0): DHCPv4 lease renewal requested
Mar 11 09:11:34 pc-linux NetworkManager[1047]: <info>  [1646986294.6028] dhcp4 (enp6s0): canceled DHCP transaction

so now I can post this message.

Antonio Sesto
  • 173

0 Answers0