Company enterprise network-1 family applies for broadband access ADSL-2 FTTB-3 wired communication -2 metropolitan area network-1 school campus ADSL-2 accesses the Internet through the fixed IP address provided by the school-1.

External network (public network) users generally dial up the Internet through ADSL, wired communication and telephone lines. Whether an access device (modem) dials is the main behavior to distinguish whether it is a public IP in most cases (it is almost impossible for ordinary users to have a fixed Internet IP address). After dialing, you will apply for a temporary Internet IP address from your ISP. Used for enterprises (some modems in the system do not need to dial manually) to connect to the Internet. In other words, an ADSL broadband can only be used by one computer. ?

What is a public network? Intranet public network and intranet are two ways to access the Internet. Intranet access mode: the IP address obtained by computer accessing iNet is the reserved address on iNet, and the reserved address has the following three forms:10.x.x172.16.x.x to172.5438+0.x.x/.

Computers in an intranet access the Internet through a public gateway with NAT (Network Address Translation) protocol. Computers in the intranet can send connection requests to other computers on the Internet, but other computers on the Internet cannot send connection requests to computers in the intranet. Public network access mode: the IP address obtained by computer accessing iNet is a non-reserved address on iNet. Computers in the public network and other computers on the Internet can access each other at will.