Groupnets reside at the top tier of the networking hierarchy and are the configuration level for managing multiple tenants on your external network. DNS client settings, such as nameservers and a DNS search list, are properties of the groupnet. You can create a separate groupnet for each DNS namespace that you want to use to enable portions of the Isilon cluster to have different networking properties for name resolution. Each groupnet maintains its own DNS cache, which is enabled by default.

A groupnet is a container that includes subnets, IP address pools, and provisioning rules. Groupnets can contain one or more subnets, and every subnet is assigned to a single groupnet. Each cluster contains a default groupnet named groupnet0 that contains an initial subnet named subnet0, an initial IP address pool named pool0, and an initial provisioning rule named rule0.

Each groupnet is referenced by one or more access zones. When you create an access zone, you can specify a groupnet. If a groupnet is not specified, the access zone will reference the default groupnet. The default System access zone is automatically associated with the default groupnet. Authentication providers that communicate with an external server, such as Active Directory and LDAP, must also reference a groupnet. You can specify the authentication provider with a specific groupnet; otherwise, the provider will reference the default groupnet. You can only add an authentication provider to an access zone if they are associated with the same groupnet. Client protocols such as SMB, NFS, HDFS, and Swift, are supported by groupnets through their associated access zones.