Yes, the critical connection is the option to use in this case. You may also check the leases themselves in /run/systemd/netif/leases and check if the T1/T2/Lifetime are sensible, with each subsequent one higher than the prior. And if not, contact your ISP support to correct those.
** Changed in: systemd (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1776013 Title: systemd-networkd: DHCP lease lost (Ubuntu 18.04) Status in systemd package in Ubuntu: Invalid Bug description: I have a Linux router whose external Ethernet interface is configured from ISP's DHCP server. After its migration from Ubuntu 16.04 + ifupdown + isc-dhcp-client to Ubuntu 18.04 + netplan.io + systemd-networkd, I noticed that systemd-networkd plays overly fairly when it can not get a timely renew response from ISP's DHCP server: it honestly removes the dynamic IP from the interface and restores (often the same) IP only when ISP's DHCP server gives it a proper response again. Which causes 1..5-minute pauses in Internet availability since my ISP's DHCP server is for some reason flaky, i.e. it can become unresponsive for some periods of time. I never noticed this problem with isc-dhcp-client, and started noticing it only after migrating DHCP client role to systemd-networkd. The question is, can I (or you) make systemd-networkd DHCP client behave more relaxedly ? I know that most DHCP clients (isc-, pump, dhcpcd) at some stage of their development decided to implement such relaxed logic, i.e. to keep last-configured dynamic IP on the interface despite the lack of responses from DHCP server. As this is easier to implement than to make ISP staff fix their services, I would suppose there should be some knob in systemd-networkd settings. Or, at least, an idea to implement something similar in the future. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1776013/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp