网络名称转换网络地址_网络地址转换| 计算机网络

网络名称转换网络地址

At the time of classful addressing, the number of household users and small businesses that want to use the Internet kept increasing. In the beginning, a user was connected to the Internet with a dial-up line, for a specific period of time. But the situation turned different. Household users and small businesses can be connected by a cable modem. In addition, many are not happy with one address as many have created small networks with several hosts and need an IP address for each host. With the shortage of addresses, this is a serious problem.

在进行分类寻址时，想要使用Internet的家庭用户和小型企业的数量一直在增加。最初，用户在特定时间段内通过拨号线路连接到Internet。但是情况就不同了。家庭用户和小型企业可以通过电缆调制解调器连接。此外，许多人对一个地址不满意，因为许多人创建了具有多个主机的小型网络，并且每个主机都需要一个IP地址。由于地址不足，这是一个严重的问题。

There is a quick solution to this problem is called NAT (Network Address Translation). NAT enables a user to have a large set of addresses internally and one address or a small set of addresses, externally. The traffic inside can use the large set, however, the traffic outside is only the small set or one address.

这个问题有一个快速解决方案，称为NAT(网络地址转换) 。 NAT使用户可以在内部拥有大量地址，而在外部拥有一个地址或一小组地址。内部的流量可以使用大集合，但是，外部的流量只是小集合或一个地址。

To separate the addresses used inside the home or business (internal ones), the Internet authorities have reserved three sets of addresses as private addresses, shown below,

为了分隔家庭或公司(内部)内部使用的地址，Internet当局保留了三组地址作为私有地址，如下所示，

     10.  0.0.0 to  10.255.255.255 
172. 16.0.0 to 172. 31.255.255 
192.168.0.0 to 192.168.255.255

Any organization can use an address that may out of this set without taking permission from the Internet authorities. Globally known that these reserved addresses are for private networks.

任何组织都可以使用此地址范围之外的地址，而无需征得Internet当局的许可。这些保留的地址是专用网络专用的。

These addresses are unique in an organization, but they are not unique globally. No router will forward a packet directly to the destination that has one of these addresses.

这些地址在组织中是唯一的，但在全球范围内不是唯一的。没有路由器会将数据包直接转发到具有这些地址之一的目的地。

Address Translation

地址翻译

All the outgoing packets go through the NAT (Network Address Translation) router that replaces the source address in the packet with the global NAT address. All incoming packets also pass through the Network Address Translation (NAT) router, which replaces the destination address in the packet.

所有传出数据包都经过NAT(网络地址转换)路由器，该路由器将数据包中的源地址替换为全局NAT地址。所有传入的数据包也将通过网络地址转换(NAT)路由器，该路由器将替换数据包中的目标地址。