Port forwarding for CCTV

[circadianswing]

I have C6300 that is successful in utilizing dyndns for CCTV DVR outside of my home LAN.  However, within the 192 LAN, utilizing the DynDNS hostname, simply points me to the router admin page. In order to see the CCTV DVR internally, I must specify the 192.x address.  I'm on time warner cable, and this has been an issue for me since I purchased your combo flagship modem/router.  Is there any fix for this, and if so, a step by step on how to make the dyndns host name work both internally and externally to the target device?  Much appreciated.

[Babylon5]

The ability to use the Public IP or external URLs from within your LAN depends on whether the router supports ‘Loopback’, many older Netgear home grade routers do not, and only some of the newer routers do, for example the R7000 does. The C6300 is intended for use with specific ISPs and contains firmware which is ISPs approved and some features may be removed/disabled, so it may be that the C6300 does not support loopback.

[circadianswing]

Thanks for your reply, I have been told that is the "loopback" feature; however, using TWC's own cable modem (arris) I believe with a netgear router, and subsequently using a newer TWC modem/router unit didn't have this issue either.  Why would they block netgear?  I have seen many posts in this forum on the matter, and note the firmware has not been updated since I purchased th unit in early 2015.   Surely Netgear could advise TWC on these matters, being a certified provider of equipment on their network?