In the firewall settings on a Netgear DG834GU modem/router I am trying to create an inbound rule that allows SMTP traffic (port 25) only from an address range (only allow mail from Postini anti-spam service).
Under WAN Users I select Address Range and enter start 188.8.131.52 and end 184.108.40.206.
An error appears when I try and save: "Invalid destination start ip, please enter again, Invalid finish ip, please enter again".
I also tried entering as an IP/subnet pair but same error.
Why wouldn't this work?