Clever Use of soft routes solves network access switching Problems

[51cto exclusive Article] to improve office efficiency and communicate with each other, many organizations have established local LAN networks, employees can freely share information or access network printers with each other through the LAN platform, and share access to the Internet through the lan network. However, sometimes, for some special server hosts, they sometimes need to connect to both the LAN and other special networks. When each workstation has only one Nic device, how can we change the network connection so that the workstation can quickly access different types of networks? In view of this, this article specifically sets the method of enabling soft routing and configuring dual-connection parameters for each workstation to quickly and effectively solve the problem of network access switching!

Organization networking status

The Planning Office of the organization, for work reasons, connects all workstations in the office together with a 24-port switch of A TP-LINK brand before the Organization has established a local lan network, form a small LAN (for convenience, this article calls this lan network ), several colleagues at network planning a can easily share files or printers. Later, the higher-level department asked to establish a vertical network for each system. At this opportunity, the organization established a LAN (which corresponds to the previous network called B network ); to ensure the stable operation of Network B, the network administrator of the organization binds the IP address of each workstation to the physical address of the network card, which facilitates future network maintenance operations, it can effectively avoid frequent IP address snatching in the LAN. To facilitate the connection between each office and the B network, the Unit reserved an interface connecting the B network for each office. The Planning Office uses a direct network cable, connect the up-link port of the switch in the room to the LAN reserved interface to achieve physical connection between network A and Network B.

After establishing a local lan network, the organization's leaders agreed to lease a 2 m optical fiber line of a local broadband operator to facilitate work and achieve direct connection between the lan network and the Internet network, in this way, All workstations in various offices of the Organization can share the Internet through the LAN. However, due to the rampant spread of viruses and trojans on the Internet, it is difficult to ensure that the workstation is directly connected to the Internet without being attacked by network viruses and Trojans. The Planning Department is special in this office, generally, you need to report various project information online to the higher-level department through VPC. If the workstation is accidentally infected with a network virus or Trojan, it will not only affect the efficiency of project reporting, and may also cause the loss of important project information; for this reason, the room and specially purchased an ADSL dial-up Internet equipment, the device and the TP-LINK switch connected together, all workstations in the Planning Department can use this device to perform ADSL dial-up Internet access and connect to the Intranet of the higher-level department for online application materials. At the same time, when the workstation is connected to the internal network of the higher-level department, each workstation uses the IP address of Network A. To Access Network B, you must change it to the IP address of Network B. In Network B, a dedicated DHCP server is set up, therefore, when connecting to Network B, you only need to modify the online parameters of the workstation to automatically obtain the IP address.

Network switching troubles

For work reasons, All workstations in the Planning Office usually need to switch to the Internet in two different networks, and only one Nic device is installed in each workstation, in this way, each time you want to access the internal network of the higher-level department, you need to change the parameter of the workstation in the office to the IP address of network a. When you need to access the LAN in the future, it is also annoying to change the online parameters of the workstation to the IP address of the B network. However, in the Planning Office, when we try to connect to the B network from a common workstation, we find that some workstations in the office can access the LAN normally, but some cannot access the LAN normally, why? Every time I switch to a different network environment, do I need to constantly manually modify the online parameters of the workstation?

Solve network switching Problems

Considering that all workstations connected to Network B obtain IP addresses from the DHCP server of the LAN, before formally Accessing Network B, the author tries to open the workstation network connection in the Planning Office, enter the TCP/IP attribute settings window, and select the "automatically obtain IP Address" option (1). In this way, the Network B can be accessed smoothly, however, I found that the target workstation could not access network B. Is it because the workstation in the Planning Office could not obtain a valid IP address from the LAN DHCP server?

 

Figure 1

To check whether the faulty workstation has obtained an appropriate IP address from the DHCP server, I specifically switched the System of the target workstation to the doscommand line working status. At the command line prompt in this status, run the string command "ipconfig/All". On the result page shown in 2, the IP address used by the target workstation system is "10.176.34.168 ", however, this address is obviously not allocated by the DHCP server in B because the address pool set by the DHCP server ranges from 192.168.0.2 to 192.168.0.254, is there another DHCP server in the lan? After careful check, I found that the ADSL dial-up Internet access device used in the Planning Office also comes with the DHCP service function, and this function has been set and activated by people in the network company, the IP address 10.176.34.168 obtained by the previous target workstation is actually allocated by the DHCP server. Using this IP address, the target workstation will naturally fail to access the B network.

 

Figure 2

After finding out the specific cause of the fault, I immediately disabled the DHCP service function provided by the ADSL dial-up Internet access device, then, execute the string commands "ipconfig/release" and "ipconfig/renew" in the faulty workstation. As expected, the faulty workstation can immediately access the B network again.

Although it solves the problem that the workstation in the Planning Office cannot normally access the B network, switching should be performed every time you access different networks, which will not improve work efficiency, it is also very troublesome. can we enable Windows to automatically switch the network connection when the workstation only installs one Nic device? The answer is yes, because Windows XP comes with a soft route function, as long as you cleverly use this function, we can enable the Windows system to automatically switch the network connection, the following is the specific switching operation steps:

First, open the "Start" menu on the workstation in the Planning Office, and click "set"/"network connection" commands in sequence. In the displayed network connection List window, right-click the target local connection icon and execute the "properties" command from the shortcut menu to open the attribute setting window for the target local connection, select the "Internet Protocol (TCP/IP)" option in the settings window, and click the "properties" button under the option to open the attribute Setting dialog box for the corresponding protocol options.

Then, on the "General" tab page of the Settings dialog box, select the "automatically obtain IP Address" option, and click the "alternate configuration" tab to go To the tag settings page shown in 3, on this page, select the "user configuration" option, and enter the IP address, subnet mask, gateway address, and other parameters corresponding to Network A in each text box, assume that the IP address of the network is 10.176.34.168, the gateway address is 10.176.34.1, And the subnet mask is 255.255.255.0. Click OK to save the preceding settings.

 

Figure 3

Next, open the "Start" menu of the corresponding workstation system, click the "run" command, enter the "cmd" string command in the system running text box that appears, and click the Enter key, switch the system working state to the MS-DOS command line working state, and enter the "route-P add 10.0.0.0 mask finished 255.250.0 10.176.34.1 metric 2" string command at the command line prompt in this state, click the Enter key, A new route record pointing to Network A is added to the local route table of the target workstation. In accordance with the same operation method, we set the Internet access for other workstations in the Planning Office in sequence, manually add route records pointing to Network.

After the above settings, the workstations in the Planning Office will first obtain the appropriate IP address from the lan dhcp server by default, so that the workstation can automatically connect to the B network. When we try to access network A, the Windows system will also give priority to access network B. However, when the access fails, the system will automatically use the standby Internet parameters, and access to the network smoothly through the soft route records of the local system. In this case, we do not need to switch manually in the future, this allows the workstations in the Planning Office to switch freely between two different network work environments.

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