Docs / IPAM

Addresses (prefixes and subnets)

Nested prefixes on Addresses. DHCP or tracking-only. Open a subnet to mark an address.

Open Addresses (/plan). Nested prefixes and their child subnets, with utilization (leased / reserved / assigned / excluded). Click a subnet CIDR to open it.

Addresses: prefixes with a DHCP subnet and a tracking-only subnet

Addresses: prefixes with a DHCP subnet and a tracking-only subnet

There is no checkbox named “used.” Pick the object:

  • Reservation — DHCP client always gets this IP (MAC, DUID, or client-id). Counts on the license.
  • Assignment — static server, no DHCP. Counts on the license.
  • Exclude — gateway, VIP, a hole with no identity. Does not count.
  • Lease — what dhcpd already handed out. Search or Leases.

A subnet is DHCP (needs a pool) or tracking only (static servers, no DHCP). Next free IP is in the plan, not only in the pool.

Create a prefix

Admin only. Add a CIDR and optional description (example: 10.10.0.0/16 as the container). Prefixes nest; they are the drawing, not the DHCP scope.

Create a subnet

Under a prefix, create a subnet whose CIDR is the broadcast domain (example: 10.20.20.0/24). Then on the subnet screen set:

  • Gateway
  • VLAN, site, VRF (optional)
  • Lease time (seconds, default 86400 / one day). Campus default; guest is hours, not 30 minutes — DHCP lease time
  • Authoritative
  • DDNS on/off, adapter, forward zone, reverse zone
  • NTP servers (option 42)

The DHCP plane reads these rows. There is no second “ISC config” to keep in sync. Renew/rebind (T1/T2) can be stored on the subnet; they are not yet sent as DHCPv4 options 58/59.

Pools, reservations, excludes, and options are on the same subnet page. Walk-through: First subnet. See Subnet.