Does this post help from Linux.org?:
As an aside, have you got ufw up and running? also see here:
You may also want to consider ipfire: https://www.ipfire.org/
Other recommendations made to me is to buy a cheap 4Gb RAM 2.4 GHz small Dell desktop pre-configured with pfsense: https://www.pfsense.org/
So to the house it is Router, to box with pfsense then from firewall pc to switch to network connections.