Samir

There's three different ways I'd approach the problem of isolating the cameras, all with different price points. Most expensive: Get a router that does vlans and more complicated routing. You can find used business-class equipment like the netgear fvs318n on craigslist pretty cheap, but otherwise, you're looking at ~$150 Second-most expensive (and maybe not less by much) Get a router that has a DMZ that does NOT allow DMZ traffic onto the local lan. Then your cameras are fully exposed, but your LAN is completely safe. Unfortunately, these routers are typically in the same class as those that can do vlans, so the cost will be nearly the same. Cheapie route: Use a second cheap router to create a 'double-nat'. The second router would be behind the first (wan of second into lan of first, cameras in first). This will allow your cameras to be accessed from outside, but that's it (unless you add additional forwarding to your lan which sits on the second router). Your lan will have access to the cameras because they will be treated like 'wan' addresses. This is probably the cheapest and easiest. Cheap second router ~$20-25 at walmart, and nothing new to learn about vlans, dmz, etc.

Definitely sounds like a software issue on the other systems. jazzar is right about all the settings--they can be a nightmare, especially since some of them that are necessary for viewing the video stream can make your system more susceptible to badware from the Internet.

From what it sounds like, you're doing some sort of LAN presentation that you want people to see. Something like teamviewer or gotomeeting works when you are on the Internet, but for LAN usage without Internet, these won't. However, I'm sure there's some privatized pieces of software designed to do exactly what you want. I'd search for 'LAN presentation' software and see what you come up with.

I think this would be a fairly easy solution to set up since the slingbox service (and similar ones) connect to a cloud which you connect to. In fact, any service like this might do exactly what you want. The other way would be via a vpn, but you have to connect to a cloud vpn and then access that. I don't think that's as simple as the video output method, but it would be 100%, allowing you to have the full range of controls normally available.