Resolving IP address conflict issues

What about IP address conflicts? How do I resolve a LAN IP address conflict?

In the same LAN, if two users use the same IP address at the same time, or if a user has already obtained an IP address through DHCP, and another user has assigned the same IP address manually, this will cause an IP address conflict and will make it impossible for one of the users to use the network properly.

So how do you avoid an IP address conflict? We can analyze from the following aspects:

　The reason for the IP address conflict occurred:

1, many users do not know the "IP address", "Subnet mask", "Default gateway" and other parameters how to set, sometimes the user is not from the administrator to get the information above, or the user has no intention to modify this information caused;

2, sometimes the administrator or user based on the parameters provided by the administrator to set up, due to errors caused by the wrong parameters will also lead to this situation;

3, appears most is in the client maintenance debugging, the maintenance personnel uses the temporary IP address application to cause;

4, also does not rule out someone steals other people's IP address, causes the IP address conflict.

Solution for LAN IP address conflict:

　　Plan one: the investigation.

This is the most original method, that is, when the IP address conflict, in the local area network, next to each computer to see, to find its conflicting computer to modify the IP address can be. However, this is more time-consuming and not suitable for use in large LAN, only suitable in a very small network environment to use.

　　Scenario Two: MAC address binding.

1, check the local computer Mac and binding: through the local computer system running Winipcfg.exe or Ipconfig.exe, you can know the MAC address of the network card. The following: In the Win9x system, click Start-Run, enter "Winipcfg" in the text box and return to the "IP Configuration" window. Select PCI Fast Ethernet adapeter in the Drop-down list, and the text displayed in the adapter address bar is the MAC address of the NIC, and the ipconfig command with the "all" parameter is run at the DOS prompt of the Winnt system. That is, Ipconfig/all can also display the MAC address of the NIC.

2, the remote test computer MAC address: For network administrators, you can use the Tcpnetview tool software to realize sitting in front of their own computer can be measured in the local area network of all computers MAC address. After the installation is completed, the program will be tcpnv.exe to display the main window, select the "Refresh" command in the "File" menu, or press "F5" key to begin scanning the existing computer on the LAN, and then display the computer name, IP address and MAC address. When waiting for a computer network card MAC address, it can be recorded, by the gateway or firewall on the configuration can be. The specific binding commands vary depending on the gateway or firewall used, and if there are other computers that want to use the already-bound address, a hint that the IP address is already in use will appear.

　　Scenario Three: Switch security ports.

In the past, routers and hubs were used in the network, and many LANs now switched to switches. With the sharp price reduction of switches in recent years, the switch occupies a dominant position in the network market, mainly because of its high cost-performance and flexible structure, which can be flexibly configured with the change of future application. For the IP address conflicts encountered, you can also use the port of the switch to isolate different departments to resolve, because the use of the switch can be different areas of different management, divided between the network segment to a certain extent, can solve the problem of IP address conflicts.

　　Scenario four: Divide the VLAN.

Although the switch can be used to achieve network segment isolation, to some extent to avoid the occurrence of IP address conflicts, but it still does not prevent the network segment under the same port due to user configuration errors caused by IP address conflicts. A better solution would be to use the switch to divide the VLAN, and then use the MAC address binding method to deal with it comprehensively.

Personal IP Address conflict resolution

1. If the operating system of the computer you are using is: Windows 98

Click on the lower left corner "start" → "Run", type: Winipcfg, click "OK", in the pop-up window, click "Release All", and then click "All Update", you can resolve the problem of IP address conflict.

If you are prompted not to update, you will need to restart your computer.

2. If the operating system of the computer you are using is: Windows 2000 or Windows XP

Click on the lower left corner "start" → "Run", type: Ipconfig/release, click "OK", click "Start" → "Run", type: ipconfig/renew, click "OK", you can resolve the IP address conflict.