DHCP lease

What it does: shows how THIS machine got its IP address. If it's using DHCP (most machines do), it lists the DHCP server that handed out the address, the assigned IP / gateway / DNS, and — from the OS lease record — when the lease was obtained and when it expires. If an interface is set static, it says so.

What you need: nothing — press Refresh. The summary comes from the OS network stack; the lease detail comes from ipconfig /all (Windows) or the dhclient / systemd-networkd lease files (Linux). Those lease files can need root on some Linux setups; if so, the summary still shows the server and addresses. Nothing leaves your machine.

Safe to run: yes — it only reads.

What to expect / reading results: check the DHCP server is the one you expect — a lease from a ROGUE or wrong DHCP server (a mis-plugged home router, a second server on the VLAN) is a common cause of "I got the wrong IP / gateway / DNS." The obtained/expires times show how fresh the lease is; a very short lease, or one that won't renew, points at a DHCP scope that's exhausted or a reachability problem to the server.