At 05:03 AM 9/10/2002, Paul Hess wrote: >Could someone point me towards a simple resource or a calculator program to >understand the *.*.*.*/XX notation and how to convert it to an address range?
I always like it when I get to figure out something that I'm fuzzy on so that I can explain it. :) Hope this helps. this is used to set a subnet with more granularity, so you don't have to assign 253 addresss (a class C range or X.X.X.0-X.X.X.255 (roughly)) or multiples thereof and so that if you want less than a class B range (X.X.1.0-X.X.255.255) you have a simple way of defining it. Some apps use the / notation but end-user apps generally don't. The /X number tells you how many bits are part of the range. /24 means the first 24 bits are masked. This is the equivalent of a class C range (X.X.X.0-X.X.X.255 (roughly)). /25 in this case means that the first 25 bits are masked. In this case, it means that we start at 64.75.1.128 and we include the next (32 (total bits) - 25 (the mask) = 7 ) (2^7=128) 128, so we know this domain goes from 64.75.1.128-64.75.1.255 If it was /23, it would be 2^9 or 512 addresses from 64.75.1.0-64.75.2.255. Note the weirdness: The range says it starts with 64.75.1.128, but because the mask doesn't allow it, it would really start with 64.75.1.0! And it might screw up some apps by doing that. There are all sorts of special rules about what does and what does not work, including the "all ones" and "all zeros" rules. This link explains a bunch of it. http://www.gtoal.com/subnet.html Calculator: http://www.agt.net/public/sparkman/netcalc.htm >-------------- Michael Croft "Babeheart? What's it about?" mailto:[EMAIL PROTECTED] it's about a cute little pig that http://www.whiterose.org/michael slaughters the English" -- Freakazoid >-------------- ############################################################# This message is sent to you because you are subscribed to the mailing list <[EMAIL PROTECTED]>. To unsubscribe, E-mail to: <[EMAIL PROTECTED]> To switch to the DIGEST mode, E-mail to <[EMAIL PROTECTED]> To switch to the INDEX mode, E-mail to <[EMAIL PROTECTED]> Send administrative queries to <[EMAIL PROTECTED]>
