Can anyone help understand subnetting... i have a Cisco SMB SRP541W unit.
this is what is is, i want to create a fw rule to allow traffic from a host based on its IP address, let's say that i want to allow traffic from 18.104.22.168 to my network, i don't know the source's subnet mask, just the IP. When i create a rule i enter the IP address but a subnet mask is required, i entered or 0.0.0.0 and it fails (meaning the rule can't be create). if i use 255.255.255.255 it seems to create the rule but is it right? Is the latter one the right choice if i don't know the source's sm?