如果每个subnet的number of hosts不多,动不动就用整个Class C subnet用coverage,那么就有点浪费,如果我们能处理好一点,在Class C下都可以分成很多歌subnets的,怎样分,那么主要看subnet mask怎样设。
/24 1 set of 256 hosts (0-255), where 0 and 255 are not used for hosts/routers
/25 2 sets of 128 hosts (0-127, 128-255), where 0, 127, 128, 255 are not used for hosts/routers
/26 4 sets of 64 hosts (0-63, 64-127, 128-191, 192-255), where 0, 63, 64, 127, 128, 191, 192,255 are not used for hosts/routers
/27 8 sets of 32 hosts (0-31, 32-63, 64-95, 96-127, 128-159, 160-191, 192-223, 224-255), where 0, 31, 32, 63, 64, 95, 96, 127, 128, 159, 160, 191, 192, 223, 224 and 255 are not used for hosts/routers
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