Leases¶

Leases are read live from Windows and shown on a Leases tab of the sys4 subnet page. They are not stored in NetBox models, and NetBox IP addresses are not updated from them.

Reading the leases of a scope¶

Open a subnet that belongs to a Windows server (directly, or through a shared network). The Leases tab appears next to the subnet's other tabs.
Click Load leases. A background job connects to Windows and reads the scope's IPv4 or DHCPv6 leases.
The panel refreshes itself every few seconds while the job runs, then shows the result.

Column	Meaning
IP address	The leased address
Client ID or DUID	The MAC address (IPv4) or DUID (DHCPv6) of the client
IAID	DHCPv6 only
Host name	As the client reported it
State	The Windows address state, for example `Active` or `ActiveReservation`
Expires (UTC)	When the lease ends, as Windows reports it
Description	The Windows lease description

Leases are sorted by address. At most 5000 are kept from one read; above that, the panel says how many there are and shows the first 5000.

How reads are kept¶

Only the latest read of a subnet is kept, in the data of its job. Each new read deletes the earlier ones.
The job belongs to the Windows server (sys4 subnets cannot hold jobs), so the read also appears in the server's jobs, for users who may view jobs.
One read per subnet waits or runs at a time; clicking again meanwhile does nothing.
A read still waiting or running after 15 minutes counts as lost (the worker may have stopped): the panel says so and you can load the leases again.
A failed read shows its reason, for example a scope that no longer exists on Windows.

Who can see and load leases¶

Seeing the tab needs view on the subnet and on its Windows server (object permissions included).
Loading leases connects to Windows, so, like the connection test, it needs change on the Windows server too.

Branches¶

Leases are read for the subnet as it is in main. Inside a branch the Load leases button is hidden and reads are refused: switch to main.