Netapp exports and nfs.netgroup.strict option

Had issues with hosts mounting NAS qtrees exported from filer earlier and it turned out to be due to nfs.netgroup.strict parameter

per exports man page:  A netgroup can be differentiated from a hostname by prepending an `@’ to the name. When an entry begins with an `@’, ONTAP treats it as netgroup and not a hostname. When an entry does not begin with `@’, the handling depends on the setting of the option nfs.netgroup.strict.

If nfs.netgroup.strict is set, then the `@’ determines whether an entry is either a netgroup or a hostname. In this case, when an entry appears without a prepended `@’, it is assumed to be a hostname, i.e., it cannot be a netgroup.

If nfs.netgroup.strict is not set, then an entry with `@’ will still only denote a netgroup, but the absence of the `@’ does not determine that an entry is a host.