The computer can't get the IP address? Maybe it's the private DHCP.

DHCP service is used to assign IP addresses to clients in the local area network, so as to achieve unified IP address management, which can effectively simplify the configuration process and prevent exceptions such as IP conflicts. But sometimes we find that computers can't get IP. How to diagnose at this time? There are two situations:

All computers can not get IP, it can be judged that there is something wrong with the DHCP service, generally need to check and restart DHCP.

Only individual computers can not get IP, first of all, the network cable contact problems and system problems should be eliminated.

In practical work, it is found that even if there is no problem with the network cable and the system, sometimes the IP will not be obtained. How did this happen? Please read on.

A WSG gateway user reported that a computer would not be able to get IP. After our remote technical support, we found the following DHCP log:

The process goes something like this:

The client said, give me an IP.

The server said: please use 192.168.0.116.

The client said, "can I use 10.10.10.10?"

The server said: no.

And then? There's no such thing as then. The customer is prompted that the IP is not available. So who caused this phenomenon? Experienced technicians can think for themselves. The answer will be presented later.

At first, the stupid little donkey was also very strange, and he couldn't understand it for a long time. He didn't know until he asked us how good he was. This is the 10.10.10.10 lease that was previously assigned, which is not yet over, so the client will ask for this address of the 10 segment. Doesn't this mean that there are other DHCP services in the network segment? I quickly scanned it with the DHCP scan plug-in, and sure enough:

Two DHCP services were scanned.

After stopping a DHCP service, the problem is solved!