When building a local area network, the biggest application is the sharing of document resources, audio and video resources, and printer sharing. As the use time goes by, many problems will inevitably arise in the network environment due to the influence of software and hardware. This chapter lists some common problems in resource sharing, and hopes to give readers a reference for exclusion. At the same time, some relevant knowledge has been prepared for everyone to understand, so as to make it easier to understand and understand the essence of the problem.
Example 1: How to achieve mutual access in different network segments
Question: The IP addresses of the two departments are similar to "192.168.0.1" and "192.168.1.1", and their subnet masks are both "255.255.255.0". They belong to different network segments. How can they access each other?
Analysis and Solution: When more than two network segments must exist in a local area network, the hosts divided into different network segments are invisible to each other. If they want to visit each other, they must set up routing. There are two relatively mature solutions at present. One is to purchase a special router to implement it, which is characterized by powerful functions and fast network access speed. The disadvantages are also obvious: it costs thousands of yuan to purchase hardware equipment.
If you use the IP routing function of Windows 2000 Server (also known as a virtual router), it not only saves costs, but also is convenient and fast. The implementation steps are:
1) Install two network cards on Windows 2000 Server machine and configure them as different network segments.
2) Install the IP routing function. Click "Start\Programs\Administrative Tools\Routing and Remote Access" to open the "Routing and Remote Access" window; click the "Operation" menu, select the "Configure and Enable Routing and Remote Access" command, and after running the wizard, select the "Network Router" option in the "Public Settings" window; finally install the TCP/IP protocol and do not install the remote access service, so the routing function is enabled.
3) In order to enable each computer in different network segments to access each other, each computer needs to set the IP parameters so that its gateway and DNS addresses point to the IP address of the virtual router.
Summary: To achieve mutual access by computers of different network segments, they need to establish an access channel for this, which is "routing".
Example 2: What is the use of "127.0.0.1" IP address
Question: When building a web server, I came into contact with the IP address "127.0.0.1". What is its use?
Analysis and solution: "127.0.0.1" is a native address, which is mainly used for testing; in addition, it has an alias called "Local host". Therefore, there will be no computer with "127.0.0.1" as the IP address in a network. In addition to this address, there are many special IP addresses that cannot be used indiscriminately, such as:
1) "255.255.255.255". The name of this network IP address is "Restricted Broadcast Address". This address cannot be forwarded by the router. For this machine, it represents all computers within the same network segment.
2) "224.0.0.1", this is a multicast address, specifically referring to all hosts, and the other 224.0.0.2 refers specifically to all routers; in fact, from 224.0.0.0 to 239.255.255.255.255 are multicast addresses. In general, this type of address is used for some specific program.
There is also an IP address "169." If the machine automatically assigns an IP address (DHCP function) through the server, when DHCP fails, the system of the machine will feedback such an address.
Summary: Normally, these special IP addresses are not assigned to any host and are only used to represent the network address of a certain network.