(16 Feb 14, 10:04PM)Mousikos Wrote: So let's say I have a partial IPYes, 100% correct.
A.B.C.X and so I want to block everything from A.B.C.0 to A.B.C.255, in CIDR notation, I would block A.B.C.0/24 to block all of those, regardless of what type of IP it is, correct?
Quote: And then... from what I gatherAbsolutely right.
24 specifies the number of bits until you don't care right? So if it's 8 instead of 24 you block a hell of a lot of IPs?
For those who don't understand the 'bits' part, if you write a dotted decimal IP as binary, it becomes aaaaaaaa.bbbbbbbb.cccccccc.xxxxxxxx, with each letter representing one bit (either a 1 or a 0). Ignoring the first 24 leaves you with just the x's (only 256 hosts max.), and ignoring only the first eight leaves you with 1/256 of the IPv4 address space blocked.