First, the network knowledge
1, the network : applications, including network deployment, the default can only be used within the network address in the same interconnection access within a local area network, external network access to other network environment is visible.
2, penetration : two-point direct connection, such as two computers through a network cable, the penetration speed is not limited, the smaller the speed is the speed between the two ends of the end speed.
3, the mapping : mapping an address to another address, a transit through a media, often used to map the network address to the external network address is implemented in the access network, the speed of the line and the local public network mapping server allocated more small value rate.