How do I tell the user what to use for an IP netmask?
The whole netmask business is a complicated one. An IP interface has an IP address and usually a netmask associated with it. Netmasks on point-to-point interfaces like a PPP link are generally not used. If you set the Framed-IP-Netmask attribute in a radius profile, you are setting the netmask of the interface on the side of the NAS. The Framed-IP-Netmask attribute is NOT something you can set to influence the netmask on the side of the dialin user. And usually, that makes no sense anyway even if you could set it. The result of this on most NAS is that they start to route a subnet (the subnet that contains the assigned IP address and that is as big as the netmask indicates) to that PPP interface and thus to the user. If that is exactly what you want, then that’s fine, but if you do not intend to route a whole subnet to the user, then by all means do NOT use the Framed-IP-Netmask attribute. Many NAS interpret a left-out Framed-IP-Netmask as if it were set to 255.255.255.255, but to be c
