This value sets whether this secondary VLAN is isolated (all connected hosts are Layer 2 separated from each other, with at most one isolated VLAN per private VLAN domain) or community (a group of mutually trusting ports that can talk to each other, with multiple community VLANs allowed per domain). Admins choose isolated for ports that should never talk to each other directly, such as guest devices, or community for a trusted subgroup like a set of servers that should communicate among themselves. Setting a secondary VLAN's type to community would let its member ports exchange traffic with each other while still being isolated from other secondary VLANs in the domain.