A quick review – your router is assigning IP addresses using the range 192.168.1.100 through 192.168..1.199. We’re going to use IP addresses that are not in that range.
Let’s say we want to use 192.168.1.51 for the first camera, and the router says that one of the cameras (it doesn’t really matter which one) is using 192.168.1.183. In a browser address bar, type http://192.168.1.183 and press enter. You should see a login page for your camera. Usually the username is “admin” and the default password is usually “admin”. The documentation that came with your camera should tell you the login default values. Go ahead and log in.
Now we want to access the network settings, specifically the TCP/IP data. We want to use a dedicated IP address, and we will set it to 192.168.1.51. The netmask value should be 255.255.255.0, and you can set the DNS value to 8.8.8.8 (that’s google’s dns servers). Next is the single most important change you will make. We want to set the gateway IP address to a value that cannot act as a gateway to the public internet. Usually the gateway address is the router’s IP address, something like 192.168.1.1, or maybe 192.168.1.254. Let’s use 192.168.1.50. That is not a valid gateway but it is a valid IP address.
Why do we want use an IP address as a gateway when it isn’t a gateway? So that the cameras cannot communicate with the public internet, only with your local network.
I cannot over-emphasize the importance of this last step. Failing to do this will leave the door open to a hacker gaining access to your video streams. You do not want that to happen.
Now on the configuration page, change the camera password. Do not leave it at “admin”. Save your changes. You’ll lose the connection to the camera, but that’s because you changed the IP address. Go to http://192.168.1.51 and it should be patiently waiting for you there. Log in using the updated password to make sure it works. Also, as a double-check, try logging in using the default password of “admin”. It should NOT work.
If you’ve connected multiple cameras, go through the same process with each one in turn. The next camera will use 192.168.1.52, then .53, and so on. Write down the IP addresses you use, and the passwords for each one. It will make things simpler if you use the same password for all of the cameras.
When you’ve finished this, you’ll have cameras connected to your network, updated passwords, and dedicated IP addresses for each one. The cameras will not have access to the public internet, only to your local network.