7/22  /sbin/iptables -t nat -A POSTROUTING -s 10.1.1.0/24 -o eth0 -j MASQUERADE
      In the above line what is the point of the /24 ?
      Is it saying "this class C."  If so how does "24" relate to that?
      What would /8 be?
      \_ Yes it is -- it means the first 24 bits of the address are the
         network address, and so the last 8 bits specify a host on that
         network.  If it were /8, that would be a class A: the first 8
         bits are the network number, and the last 24 bits are for all
         the hosts on that network.
        \_ It's standard CIDR addressing. Nowadays, you can get IP chunks that
           are /22's and so forth, so "Class C" doesn't always make sense.
           CIDR is also referred to as classless routing.
           \_ Classless Inter-Domain Routing even!
        \_ I thought the second number is the number of bits in the subnet
           mask. /24 is the same as 255.255.255.0. In practicality, the
           example is the same. --dim
           \_ Exactly: an IP address specifies both a particular network and
              a particular host on that network, and the netmask tells you how
              many bits of the address are for the network part.
              --original responder
        \_ The submask binds the parity bit, that denotes Class A
           or Class B, for upstream data logging.