Cramming down the basics.
router
Used to connect together different LAN. It exists in the network layer, using the ip address.
There are two parts, WAN and LAN, WAN is used to dial-up, is to make the route a section of its own access to the Internet, LAN is used to exchange data within a local area network, external network cable plugged into the WAN port, we connected to the computer via the network cable LAN port. Router built-in DHCP server ,
Dynamic Host Configuration Protocol is a local area network protocol. Controlled by the server refers to the range of IP addresses, it can automatically obtain an IP address and subnet mask assigned by the server when the client logs server.
IP can be automatically assigned to your computer using the route, so they will be able to plug directly online.
Bridge
A data link layer products, in order to reduce the HUB broadcasting, a local area network to improve network performance appears. It is connected to two LANs store and forward device, or can extend from the range of the network, but also can improve network performance, reliability and security.
In the hub
When the physical layer device to receive data packets from one port, other ports will put forward a package because it does not know and can not know who sent this package is the (physical layer device only concerned with voltages of these physical concepts), it can only be broadcast to everyone and let them deal with their own.
Communication between a local area network consisting of the inside, by a large number of hosts are arp broadcast
The ip address into a mac address
To distribute data, in order to reduce the media in a shared environment contention (ie conflict), it had a bridge, its role is to be divided into a broadcast domain of a small collision domain
All directly connected together, but must compete Ethernet bus nodes can be considered in the same collision domain, it means that only one device to send information, the other can only wait.
Forwarding information selected by the address and route traffic between workstations on a network limited to within the range of the network segment, and does not flow through the bridge to the other segments. Can be obtained to reduce the effect of traffic, thus increasing the available bandwidth, but the broadcast domain
Broadcast domain is a logical group of computers, all computers in the group will receive the same broadcast information.
Still has not changed.
switch
Evolved from the bridge, also belong to the data link layer. There are generally two-port bridge, and a plurality of switch ports, so the switch can be seen as a set of a plurality of bridges . Because the switch is capable of supporting a plurality of ports, the network can be (the Network) system (System) divided into a more physical network segment, such that the entire network (the Network) system (System) having a higher bandwidth, so that the switch can be optimized the bandwidth , the same transfer rate is also faster than the switch bridge, in general, the switch is a more advanced bridge.
Gateway
Only two high-level protocols for different network interconnection. Between the use of different communication protocols, data formats, or language, or even completely different architecture systems, a gateway translator. And bridges simply convey different information, the gateway to the information received repackaged to meet the needs of the destination system. Meanwhile, the gateway can also provide filtering and security features.