BT Smart Hub 2-port Forward data

[tunesofglory]

Every couple of months or so my Smart Hub 2 gets 'full up' of port forwarding data where external ports have changed. Is that when leases have been renewed? I am not really conversant with the process. When full up this results in my remote access to my cctv system not connecting. Restarting the hub 'clears' the old data and all is well. I have changed the UPnp setting on the cctv NVR to manual and I am monitoring the situation. I do notice there are other devices connected to the hub with DHCP enabled that also change with the old data still recorded so I wonder if eventually the data will fill up again leaving me with the same situation. Is there a way to auto clear out this redundant data other than restarting?   Thanks in advance.

[Crimliar]

It's probably not port forwarding that's causing this, but some of the BT routers do seem to have an incredibly old-fashioned approach towards not freeing up LAN IP addresses.  The solution may be as simple as making sure that devices on your LAN don't randomise their MAC addresses - though this marginally reduces the security of those devices outside your LAN environment!