Portfowarding problems, everything else is fine

I tried portfowarding on a Netgear R6200v2 but then I saw there were 2 ports, internal and external ports. The port for gmod is 27015/27005 right? So do I put them in both internal AND external? I did everything else leading up to that fine, but this one part confused me so much because of my router.

Yes put start and end external to 27015. You shouldn’t have to edit internal but if you do just set it as 27015. #NetgearMasterRace

Port forward from 27000 to 27030 range, in case 27015 will be used by something else on your network.