I am a newbie and I have a question about IP cameras. I am interested in installing 2 IP security cameras in my residence. Since both cameras will be in the same LAN, do the 2 cameras have to have different port numbers?
I wouldn't think so. For example, all http traffic on the internet is port 80. It's really a matter of what port is the application that you are viewing the cameras on... what port does it want. I have yet to see a security system where you can select a port number. For any application that requires a port, all devices would use the same port.
I'm wondering if maybe we have a language barrier because the question just seems a little odd to me. I could easily be very wrong on that point. If, however your question is more about the IP address, then they will be different.
The cameras should have different IP addresses, so the web interface for each one will be on Port 80. Since they are different IP's this doesn't matter. Different ports are only relevant if it's the same host.