I have a number of clients that have a mixture of RV042 and RV042G.
The other day I configured the RV042G to restrict access access on a number of ports so that only our external IP was allowed. Tested and it worked well.
I've now tried to replicate this on an RV042 and I just can't get it to work. See the attachment.
The Source IP is our external IP of our network. But even with this setting, I'm still able to access that RDP on 3391 from another external IP.