Routing simulation software: Give your computer a routing function

Routing simulation software: to allow your computer to have the routing function, learn this technology, you will be able to avoid the cost of buying a router. You can also be a master. When you see the title, you don't think it's about routing simulation software? No, it is a common terminal and a single Nic machine.

Maybe you will say that it is not surprising that a single Nic machine is using a router, such as cisco single-arm routing ...... But here we are talking about a common machine, or even the just-installed win95 ....... In fact, it is about the basic operation of the IP protocol in a single machine. This article is one-sided because it does not have a deep understanding of the operating mechanism of the IP protocol in the terminal.

After the IP protocol of the routing simulation software is installed on the computer, it becomes the cornerstone of your Internet access. Each step of connection and every step of exploration are completed by the IP protocol group behind the scenes. The installation of the IP protocol must be bound to a network interface, that is, it must be installed with a NETWORK adapter, for example: MODEM Nic, virtual network adapter, VPN network adapter, dial-up network adapter, etc.

After the IP protocol of the routing simulation software is installed, a stack will be created for the network connection, and a local loop of 127.0.0.x will be created for you to automatically obtain or wait for you to manually set an IP address, publish yourself to the network and explore adjacent protocol carriers, listen for packets from the network, and communicate with each other according to network rules such as DHCP, DNS, and GATEWAY.

Different CIDR blocks in the INTERNET cannot access each other directly. You need to use the router packet forwarding function. The rule is based on an automatic or manual route information table. In fact, the packet forwarding process exists in a single machine. The ROUTE command shows us a routing information table: C: \ WINNT \ system32> ROUTE PRINT

This table shows how the single-host internal IP protocol maintains packet forwarding for different network segments. You may think that the computer PC should only exist in one network segment, here, we will look at the Protocol from a micro-perspective. In the environment of the routing simulation software, the CIDR blocks related to computer work are:

◆ 255.255.255.255 255.255.255.255 192.168.0.111 192.168.0.111 1 broadcast for network interfaces. No matter what network segment you are, LAN or INTERNET, this network segment exists. He is the basis for communication between the computer and the IP environment around him.

◆ 224.0.0.0 224.0.0.0 192.168.0.111 192.168.0.111 1 multicast address (multicast) is also a probe network. Multicast addresses use the protocols or devices represented by different multicast addresses to discover the network environment.

◆ 192.168.0.255 255.255.255.255 192.168.0.111 192.168.0.111 1 broadcast address of the computer's network. Its existence is the basis for communication with machines in the same network segment.

◆ 192.168.0.111 255.255.255.255 127.0.0.1 127.0.0.1 1 the computer's own IP address accesses the loop of its own IP address. This route defines that if this computer accesses its own IP address and does not pass through another gateway, it directly accesses itself through the 127.0.0.1 local loop IP address. It is equivalent to your own gateway.

◆ 192.168.0.0 255.255.0 192.168.0.111 192.168.0.111 1 the network address of the computer, representing a network segment.

◆ 127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1IP address of the local loop specified by the Protocol. Once the IP protocol is installed, you can use 127. X to access yourself. 127.0.0.1 stands for the unification of values.

◆ 0.0.0.0 0.0.0.0 192.168.0.1 192.168.0.111 1. It indicates application-oriented. All data packets that are not multicast, broadcast, local loop, or local IP address are forwarded and accessed through the specified gateway.

The route table simulation software configuration in the router is very difficult to ask, it is very important that the order of the table project. A reasonably ordered route table represents performance, security, and efficiency. The static route table in the local computer, as shown in the above table, also uses the selection order, from bottom to top. The loop route of the local computer is a feature of the local static route table. The route information of 127.0.0.0 255.0.0.0 127.0.0.1 1, 192.168.0.111 255.255.255.255 127.0.0.1 127.0.0.1 1 can be:

◆ Helpful. It can help people without real network environments to test local network applications. The most commonly used is the local construction of IIS, network programming, and so on.

◆ Secure. For example, many virtual subprograms, service programs, firewalls, and system processes run on a computer during startup must access or even connect to other program ports on the computer. With the local circuit, the gateway is not used to avoid system information leakage.

◆ Efficient. Reduces network traffic and uses local loops directly to reduce the error wait time for poor network quality. You can add and modify route tables on your own, such as connecting a computer to another computer to form a network. However, their network ip addresses are not in the same network segment. You can modify the static route table to achieve network communication.

Here I want to talk about the routing simulation software. Some netizens asked how to modify the static route table and communicate with different network segments. The most common answer on the internet is: "Use route to add xxx. xxx. xxx. xxx mask 255. xxx. xxx. xxx. xxx. xxx. you can add a static route to xxx metric x. "However, you need to add two.

The network protocol service objects are multi-party routing simulation software. It is not enough for only one machine to know a rule. Therefore, the static routing information of two or more machines is added to each other at the same time, both parties know how to connect to establish a connection. In this article, my understanding of TCP/IP is still quite simple. If something is wrong, please give me some advice. Appendix:
◆ Route command
◆ ROUTE [-f] [-p] [command [destination] [MASK netmask] [gateway] [METRIC metric] [IF interface]