Basic Learning: Configure communication protocols for gateways

Basic Learning: Do you know the general steps for configuring communication protocols for gateways? Does your home wireless route gateway set up a communication protocol that often gets you offline when you access the Internet? Let's take a look at the following article. all problems can be solved.

The Gateway is also known as the inter-network connector and Protocol converter. The gateway is the most complex network interconnection device on the transport layer to achieve network interconnection. It is only used for different network interconnection between two high-level protocols. The structure of the gateway is similar to that of the router. The difference is the Interconnection layer. Gateways can be used for both Wan and LAN interconnection. A gateway is a computer system or device that acts as a conversion task.

A gateway is a translator between two systems that use different gateways to set communication protocols, data formats, or languages, and even have different architectures. Unlike the Net Bridge, the gateway repacks the received information to meet the needs of the target system. The gateway can also provide filtering and security functions. Most gateways run on the application layer, the top layer of the OSI Layer 7 protocol.

As we all know, the communication protocol set up by the gateway must pass through one door to go from one room to another. Similarly, sending information from one network to another must go through a "Gateway", which is the gateway. As the name implies, a Gateway is the "Gateway" for a network to connect to another network ".

There are also many types of gateways according to different classification standards. The Gateway in TCP/IP protocol is the most commonly used. The "Gateway" mentioned here refer to the gateway under TCP/IP protocol. So what is the gateway? A gateway is essentially an IP address from a network to another network. For example, if Network A and Network B exist, the IP address range of Network A is "192.168.1.1 ~ 192. 168.1.254 ", The subnet mask is 255.255.255.0, And the IP address range of Network B is" 192.168.2.1 ~ 192.168.2.254 ", and the subnet mask is 255.255.255.0.

Without a router, the two networks cannot communicate with each other through TCP/IP, even if the two networks are connected to the same vswitch (or hub, the TCP/IP protocol also determines that the hosts in the two networks are in different networks based on the subnet mask (255.255.255.0. To realize the communication between the two networks, you must use the gateway.

If the host in Network A finds that the destination host of the data packet is not in the local network, it forwards the data packet to its own gateway, and then the gateway forwards the data packet to the gateway of Network B, the gateway of Network B is then forwarded to a host of Network B (as shown in the figure below ). The process in which Network B forwards data packets to Network.

Therefore, only when the gateway sets the communication protocol and the TCP/IP protocol can the communication between different networks be realized. Which machine is the IP address? The IP address of a gateway is the IP address of a device with the routing function. A device with the routing function has a router and a server with the routing protocol enabled (essentially equivalent to a router), proxy server (also equivalent to a vro ).

In the context of interaction with Novell NetWare, the server information Block (SMB) protocol used by the gateway in the Windows Network and the NetWare Core Protocol (NCP) used by the NetWare network) it serves as a bridge. A gateway is also called an IP router.

What is the role of the Computer Host Gateway?

Suppose your name is Tom. You live in a big courtyard. Your neighbors have many friends. At the door, there is another Uncle Li who looks at the door. Uncle Li is your gateway. When you want to play with a friend in the yard, as long as you shout out his name in the yard, he will respond to you when he hears it and runs out to play with you.

But you are not allowed to go out of the door. If you want to have any contact with the outside world, you must use the phone at the door's Uncle Li gateway. If you want to chat with your classmate James, James lives in another yard far away, and there is also a gateway for James Wang in his courtyard ). But you don't know the phone number of James's house, but your teacher in charge has a list of all the students in your class and a phone number comparison table. Your teacher is your DNS server. So you called Uncle Li at home and had the following conversation:

Tom: Mr. Li, can I check James's phone number with the class teacher? Uncle Li: Well, you are waiting. Then Uncle Li Hung up a phone number for your class teacher and asked James's phone number.) He asked him if his phone number was 211.99.99.99! Uncle Li, I want to contact James. Could you help me contact James.

Uncle Li: No problem. Then, Uncle Li sent a request to the telephone Bureau to connect Mr. Smith's phone. The last pass was, of course, transferred to Mr. Wang from the courtyard of Mr. Smith's house, then grandpa Wang transferred the phone number to Xiaoming's house.) Then you got in touch with James.

Gateway setting communication protocol: Cross-gateway technology

The current IPV4 IP address is 32-bit, which is further divided into A, B, and C according to the first few IP addresses. However, due to the rapid development of the INTERNET, IP resources are gradually exhausted, the number of IP addresses available for allocation is getting fewer and fewer, which is in serious conflict with the rapid development of the INTERNET. In the case that IPV6 is far from being fully upgraded, only the proxy server is used, convert Intranet addresses and public addresses to access the INTERNET.

The proxy server acting as an intermediary is a gateway, which brings endless troubles to the current multimedia communication system. In the case of poor IP resources, only the gateway or even Multi-Layer Gateway can access the broadband network, because the protocol of the multimedia communication system, such as H.323, must have a public IP address on both sides of the business, but how many users of the current broadband can meet this requirement?

Microsoft's NETMEETING and other multimedia communication systems are in this awkward position; cross-Gateway has become a headache. Cross-Gateway: network data passes through layer-by-layer gateways and is subject to the speed of gateway nodes, greatly reducing the network speed. Based on the underlying network protocol, the cross-gateway technology breaks through the gateway bottleneck and enables point-to-point communication between customers.

Gateway setting communication protocol: Gateway type

◆ Transmission Gateway. The transport gateway is used to establish a transmission connection between two networks. Using the Transmission Gateway, hosts on different networks can establish cascading and point-to-point transmission connections across multiple networks.

◆ Application gateway. The application gateway performs protocol conversion at the application layer. For example, one host executes the ISO email standard, and the other executes the Internet email standard. If the two hosts need to exchange emails, the protocol must be converted through an email gateway, which is an application gateway.