When using dhclient, the current lease info, including expiration time, is in /var/lib/dhclient/dhclient.leases, and contains something similar to
lease { interface "enp3s0"; fixed-address [redacted]; option subnet-mask 255.255.254.0; option dhcp-lease-time 3523; option routers [redacted]; option dhcp-message-type 5; option dhcp-server-identifier 96.113.84.141; option domain-name-servers 127.0.0.1,75.75.75.75,75.75.76.76; option domain-search "[redacted]"; option dhcp-renewal-time 2016; option broadcast-address 255.255.255.255; option dhcp-rebinding-time 3073; option domain-name "hsd1.or.comcast.net."; renew 3 2022/06/22 23:59:57; rebind 4 2022/06/23 00:23:15; expire 4 2022/06/23 00:30:45; } However, my system uses NetworkManager which, based on my research, uses its own internal DHCP client. Looking in /var/lib/NetworkManager I see
$ sudo ls /var/lib/NetworkManager/ internal-79cbd87e-9d65-4aa4-8768-88b460fd372c-enp3s0.lease NetworkManager-intern.conf seen-bssids internal-79cbd87e-9d65-4aa4-8768-88b460fd372c-ens1.lease NetworkManager.state timestamps internal-bdaf2eb0-de2e-4573-a415-214629c7b757-enp3s0.lease secret_key which looks promising. However, the lease files contain only the IP address.
$ sudo cat /var/lib/NetworkManager/internal-79cbd87e-9d65-4aa4-8768-88b460fd372c-enp3s0.lease # This is private data. Do not parse. ADDRESS=[redacted] Simple question: Where does NetworkManager keep the lease data so it knows when it needs to renew the lease?
