segment {} block

WCL block

Declares a virtual L2 switch and its subnet, DHCP, NAT, routing and peering options.

A segment {} block declares one virtual L2 switch. The lab daemon supplies its DHCP, DNS, NAT, routing and L3 filtering (see the networking model).

wcl

segment "name" {
  subnet    = "10.0.0.0/24"      // CIDR; auto-allocated from host pool if omitted
  global    = true               // owned by the supervisor, shared across labs (§9.2)
  dhcp      = true               // default true
  nat       = true               // internet egress for this segment (default false)
  routes_to = ["other_segment"]  // daemon inter-segment routing opt-in
}

Inside a segment go the DNS, routing, forwarding and filtering sub-blocks — see the segment sub-blocks. record and sinkhole may also appear at lab level (lab-wide).