[OSI] Inter-network communication process

The PC connects switch A, which makes up the intranet. The DNS Serv and the Web Serv connection Switch B make up the extranet.

Intranet communication PC1 to PC2:

The PC1 sends the data first to switch a, and switch A does not have the ARP address cache table for broadcast.

When the data is dropped to the router, the PC2 response returns its MAC address information to PC2, and switch a ARP caches the response PC1.

The PC1 gets a response and then sends the real data, and switch A sends data to the PC2 unicast through the ARP Address cache table, PC2 the response data.

Extranet Communications PC1 Access Web Serv through a browser:

PC1 sends data to switch a, when the router does proxy ARP, goes through Switch B to request DNS Serv,dns response to the original path return.

PC1 sends real data via router to Web Serv, Web site responds to request content.

Link:http://www.cnblogs.com/farwish/p/5875107.html

[OSI] Inter-network communication process