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 From:  Charles Scott <cscott at gaslightmedia dot com>
 To:  KnightMB <knightmb at knightmb dot dyndns dot org>
 Cc:  m0n0wall at lists dot m0n0 dot ch
 Subject:  Re: [m0n0wall] Blocking an IP range
 Date:  Tue, 28 Feb 2006 10:46:28 -0500 (EST)
KnightMB:
  Yes, I believe you are correct with the /20. 195.229.240.0 -
195.229.255.255 is 16 class C's which is 4096 addresses and which matches
the table below.
  If you view this message with a monospaced font, the following table
should make sense.

Chuck

 Network Type   Addresses       Subnet Mask     Classical
 /32            1               255.255.255.255 Individual Address
 /31            2               255.255.255.254 (useless netmask)
 /30            4               255.255.255.252
 /29            8               255.255.255.248
 /28            16              255.255.255.240
 /27            32              255.255.255.224
 /26            64              255.255.255.192
 /25            128             255.255.255.128
 /24            256             255.255.255.0   Class C
 /23            512             255.255.254.0
 /22            1,024           255.255.252.0
 /21            2,048           255.255.248.0
 /20            4,096           255.255.240.0
 /19            8,192           255.255.224.0
 /18            16,384          255.255.192.0
 /17            32,768          255.255.128.0
 /16            65,536          255.255.0.0     Class B
 /15            131,072         255.254.0.0
 /14            262,144         255.252.0.0
 /13            524,288         255.248.0.0
 /12            1,048,576       255.240.0.0
 /11            2,097,152       255.224.0.0
 /10            4,194,304       255.192.0.0
 /9             8,388,608       255.128.0.0
 /8             16,777,216      255.0.0.0       Class A
 /7             33,554,432      254.0.0.0
 /6             67,108,864      252.0.0.0
 /5             134,217,728     248.0.0.0
 /4             268,435,456     240.0.0.0
 /3             536,870,912     224.0.0.0
 /2             1,073,741,824   192.0.0.0
 /1             2,147,483,648   128.0.0.0
 /0             4,294,967,296   0.0.0.0         All address space