Application viewpoint: Exploring vro configuration Cases

I have learned some useful knowledge about vro configuration. So I have studied the actual cases of vro configuration. I would like to share it with you here and hope it will be useful to you. With the rapid development of network technology, enterprises and institutions can access INTERNET to share resources.

In most cases, the ddnleased line has become a common method with stable performance and good scalability. The connection of the DDN mode is simple in terms of hardware requirements, and only one router is required) and proxy server. However, the system router configuration is a tough problem for many network administrators. The following describes how to configure a CISCO router to directly access INTERNET resources through a router.

Generally, the LAN in the organization uses the reserved IP address on the INTERNET:

10.0.0.0/8:10. 0.0.0 ~ 10.20.255.255
172.16.0.0/12: 172.16.0.0 ~ 172.31.255.255
192.168.0.0/16: 192.168.0.0 ~ 192.168.255.255

Under normal circumstances, when a workstation inside the Organization directly uses a route for external access, it will be filtered out by the router configuration because the workstation uses a reserved address on the Internet, as a result, Internet resources cannot be accessed. The solution to this problem is to use the NATNetwork Address Translation function provided by the routing operating system to convert private addresses on the Intranet to valid addresses on the Internet, this allows users with invalid IP addresses to access the Internet through NAT. In this way, you do not need to configure a proxy server to reduce investment, save valid IP addresses, and improve the security of the internal network. NAT has two types: Single mode and global mode.

The NAT single mode maps many local LAN hosts into an Internet address just like its name. All hosts in the LAN are regarded as Internet users for External Internet networks. The host in the local LAN continues to use the local address.

In the global mode of NAT, the interface configured by the router maps many local LAN hosts to a certain IP address pool in the Internet address range ). When the local host port is connected to a host on the Internet, an IP address in the IP address pool is automatically assigned to the local host. After the connection is interrupted, the dynamically assigned IP address is released, the released IP address can be used by other local hosts.