Path: /subnets/{id}. Admin edits the subnet. Operator may add reservations and force-release leases.
Settings and DDNS
Admin. Save subnet writes:
- Gateway, VLAN, site, VRF
- Lease time (seconds, default 86400 / one day). Leave T1/T2 blank unless you have a reason — DHCP lease time. Renew / rebind fields exist on the form; dhcpd currently sends lease-time only (not options 58/59)
- Authoritative
- NTP servers (option 42), comma-separated IPs — NTP
- PXE next-server and boot file — PXE
- DDNS enabled, adapter (
none,bind_tsig,ad_gsstsig,powerdns_http,embedded), forward and reverse zones
A/PTR updates run on the worker, never on DHCP Ack.
Pools
- Name (e.g.
dynamic). - Start IP and end IP inside the subnet CIDR.
- Optional client class — only clients that match that class get this pool.
- Optional PD len (
pd_prefix_len) — marks an IA_PD prefix pool, not IA_NA/v4. IPv6.
Inventory for a pool expands at most 65,536 addresses.
Reservations
IP plus MAC and/or client-id and/or DUID, optional hostname. The DHCP plane cannot give that IP to anyone else. See Reservations.
Excludes
Start–end ranges that must never be leased (gateway, network gear). They shrink free on purpose.
Options
DHCP option code and JSON payload (example code 6 with {"addresses":["8.8.8.8"]}). Optional vendor. Class-scoped options live under Classes.
Live leases
The table at the bottom is this subnet only. Across the estate: search in the console or Leases.
Utilization: leased, reserved, excluded, size. When free is near 0, see Pool exhaustion.
Admin can Delete subnet. Active leases require the Force checkbox (?force=true). Delete a subnet.