network_vlan_ranges = physnet1:1:1204这句配置是什么意思

配置文件/etc/quantum/plugins/openvswitch/ovs_quantum_plugin.ini里的network_vlan_ranges = physnet1:1:1204这句配置是什么意思?按照我的理解，这里的physnet1就是一个虚拟局域网的名字而已，后面1:1024就是使用这个类型的网络时可用的ID，这个名字会在创建网络是用到，比如quantum net-create --tenant-id <tenantA_ID> TenantA_PrivateNet --provider:network_type vlan --provider:physical_network physnet1 --provider:segmentation_id 1024，不过最后这个数值并不需要在上面配置的值之间，这里的pyhsnet1就是从上面的设置里来的，他通过这一条配置和其他设备联系起来bridge_mappings = physnet1:br-ex

下面是文件/etc/quantum/plugins/openvswitch/ovs_quantum_plugin.ini里对network_vlan_ranges的一段注释：

# (ListOpt) Comma-separated list of
# <physical_network>[:<vlan_min>:<vlan_max>] tuples enumerating ranges
# of VLAN IDs on named physical networks that are available for
# allocation. All physical networks listed are available for flat and
# VLAN provider network creation. Specified ranges of VLAN IDs are
# available for tenant network allocation if tenant_network_type is
# 'vlan'. If empty, only gre and local networks may be created.
# Default: network_vlan_ranges =
network_vlan_ranges = physnet1:1000:1100