这么算

要算的无非是三个class

1 and 126 it is a Class A address.
128 and 191 it is a Class B address
192 and 223 it is a Class C address
127 is reserved for local loopback

好， 那你的第一个例子来算，
10.10.0.0--10.10.127.255 这是class A的
在第三个octet上给了128个ip, 256-128=128
所以subnetmask是255.255.128.0
network address is 10.10.0.0
broadcast address is 10.10.127.255
gateway is set by admin, most set it as 10.10.0.1
however, it is not necessary.

至于， xxx.yyy.zzz.65-xxx.yyy.zzz.94
我假设这是class C 的， ip 的范围是 64 - 95
所以有32个ip, 2^5 = 32, 所以11100000 = 224
Subnetmask is 255.255.255.224
network address is xxx.yyy.zzz.64
broadcast address is xxx.yyy.zzz.95

whatever





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