LAN && WAN && Man
LAN
Computer LAN-Local area network is a computer communication network which is interconnected by various computers and data communication devices in a small region.
Typical features of a LAN are:
Data transmission green High (up to 1000Mbps)
High geographical coverage (0.1--25 km)
Low error rate
Low price
WAN
The WAN (wan,wide area network) is also known as the remote network (long Haul network). Typically spans a large physical range, covering a range from dozens of km to thousands of km, it can connect multiple cities or countries, or span several continents and provide long-distance communications to form an international remote network.
Features: Usually the WAN data transfer rate is higher than the LAN, and the signal propagation delay is much larger than the local area network.
Mans
The Metropolitan area Network is a computer communication network established within a city, referred to as man. belongs to the broadband LAN. Due to the use of local area network technology with active switching elements, transmission delay in the network is small, its transmission medium mainly uses optical cable, transmission rate of more than 100 megabits per second.
Port mapping && Port Reflow
Port mapping is a kind of NAT, the function is to translate the address of the public network into a private address. Just as you go to the community to find your friends, do not know your friends live in which building, you ask the door security or property, because your friend has registered their information, you can ask the door security or property to find your friend's address, this is the mapping of the relationship.
Port mapping is generally used to address the need for an extranet to access a host on the intranet.
Port Reflow can be understood as:
Network of a host X by setting the port mapping can let the external network through a static IP access to him, this time if you want to let another host in the intranet visit this host X, if you can use the network static IP (such as: 211.183.46.32) to access the host X, is to do the port reflow settings. If you can only use the intranet IP, such as 192.168.1.X to access host X, and can not use the external static IP to access host x, it is not done port reflux.
Scp
You can use SSH login-based SCP commands to upload or download files from a remote host.
Download from remote host to native
SCP [-p-r ...] [Email protected] Remote host IP: Remote host directory Local host directory
Uploading to a remote host from this computer
SCP [-p-r.] Local Host directory [email protected] Remote host IP: remote host Directory
which
-P is used to specify the remote host port
-r means recursively copying folders and subfolders and files under Folders
If the file or folder is not specified in the directory that is uploaded to the remote remote host, the file or folder is automatically created and copied to the folder, which is downloaded remotely to a local folder.
Essay Knowledge record