아래의 링크에서 테이블을 찾아보면 서브네트워킹이 무엇인지 확연히
알수 있습니다. 딱 40개가 안나오는 이유도 확실하게 알수 있습니다.
http://www.ibiblio.org/pub/Linux/docs/HOWTO/mini/IP-Subnetworking .........
.....
For our C Class network number of 192.168.1.0, these are some of the
sub-networking options you have:-
No of No of
subnets Hosts/net netmask
-----------------------------------------------------------------------
2 126 255.255.255.128 (11111111.11111111.11111111.10000000)
4 62 255.255.255.192 (11111111.11111111.11111111.11000000)
8 30 255.255.255.224 (11111111.11111111.11111111.11100000)
16 14 255.255.255.240 (11111111.11111111.11111111.11110000)
32 6 255.255.255.248 (11111111.11111111.11111111.11111000)
64 2 255.255.255.252 (11111111.11111111.11111111.11111100)
-----------------------------------------------------------------------
In principle, there is absolutely no reason to follow the above way of
subnetworking where network mask bits are added from the most
significant host bit to the least significant host bit.
However, if you do not do it this way, the resulting IP numbers will
be in a very odd sequence! This makes it extremely difficult for us
humans to decide to which subnetwork an IP number belongs as we are
not too good at thinking in binary (computers on the other hand are
and will use whatever scheme you tell them with equal equanimity).
Having decided on the appropriate netmask, you then need to work out
what the various Network and broadcast addresses are - and the IP
number range for each of these networks. Again, considering only a
C Class IP Network number and listing only the final (host part)
we have:-
Netmask Subnets Network B'cast MinIP MaxIP Hosts Total Hosts
--------------------------------------------------------------------
128 2 0 127 1 126 126
128 255 129 254 126 252
192 4 0 63 1 62 62
64 127 65 126 62
128 191 129 190 62
192 255 193 254 62 248
224 8 0 31 1 30 30
32 63 33 62 30
64 95 65 94 30
96 127 97 126 30
128 159 129 158 30
160 191 161 190 30
192 223 193 222 30
224 255 225 254 30 240
--------------------------------------------------------------------
: 질문이 있는데요 최대 40개의 호스트를 지원할 수 있도록 네트워크를
: 구현하고자 할 경우 C class에서 서브넷 마스크는 어떻게 줘야 하나요?
: 꼭 좀 답변 주세요~~ 초보의 질문 이었습니다 ^^;