We're evaluating putting in an IP-based CCTV system for a third-party upcoming project (part of a wider networking project). The CCTV system is cabled as follows: Cat 6 running from each external camera to a POE switch, patch cable from switch to NVR (network video recorder basically HDD enclosure that records the CCTV).
My concern is that there will be multiple long external Cat 6 runs that are essentially very easy entry points into the network. All some one would need to do is cut the cable, put RJ45s on both ends of the cut, place a small switch in-between and then patch themselves into the switch... Apart from the couple of minutes downtime, the CCTV camera could even carry on working.
What can I do to secure the network? I can't just not connect that switch to the rest of the LAN because there are third-party apps (home automation controllers like Crestron) that we use that sit on the local network and access the NVR as well as other local area network-attached devices.