We use an apple router. My wife and I play, so we're running 2x PS4 at the same time.
It took me a bit of digging on the internet but I basically just set up individual IP#s for each PS4 and then got the ports to forward from the Sony support website.
Maybe have an issue once or twice a week. But it seems to be more on the server side than out connection (entire raid team being kicked)
Doing this got NAT Type 2 which seemed to be the issue.
No I just set up two IPs on my router and then set up port forwarding for each. Then manually set each PS4 to use the manual IP's.
With two computers an iPad and 2 iPhones in the house - not to mention when friends or older kids and their friends show up, I think everything is competing for IPs. This way I now have individual IPs for all our main devices.
EDIT: Sony updated the PS4 ports to forward in late December.