网络选项2：私有网络 in Installation Guide

[WangLei]

######
在``[linux_bridge]``部分，将公共虚拟网络和公共物理网络接口对应起来：
    [linux_bridge]
    physical_interface_mappings = provider:PROVIDER_INTERFACE_NAME
将``PUBLIC_INTERFACE_NAME`` 替换为底层的物理公共网络接口。请查看：ref:environment-networking for more information。
######

"PROVIDER_INTERFACE_NAME" "PUBLIC_INTERFACE_NAME"
Which one is it?

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-----------------------------------
Release: 0.1 on 2017-06-12 11:15
SHA: 1865f28305fdb1eb6b5e1a434ac7e292c3421513
Source: http://git.openstack.org/cgit/openstack/openstack-manuals/tree/doc/install-guide/source/neutron-controller-install-option2.rst
URL: https://docs.openstack.org/mitaka/zh_CN/install-guide-ubuntu/neutron-controller-install-option2.html