Posted on 2008-01-06 22:09
tanzek 閱讀(1477)
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讀書記錄
?在RFC 950 - Internet Standard Subnetting Procedure中有一小句這樣子的聲明：
Since the bits that identify the subnet are specified by a bitmask, they need not be adjacent in the address. However, we recommend that the subnet bits be contiguous and located as the most significant bits of the local address.
然后在RFC 1219 - On the assignment of subnet numbers對RFC 950其中的子網號設定作了一些補充，在這里就可以看到對RFC 950的一些總結：
RFC-950 [2] specifies a procedure for subnetting Internet addresses using a bit-mask.? While RFC-950 allows the "ones" in the subnet mask to be non-contiguous, RFC-950 recommends that 1) they be contiguous, and 2) that they occupy the most significant bits of the "host" part of the internet address.
在其中就可以看到RFC并不要求子網掩碼必須是連續為1的，即允許為非連續子網掩碼，不過并不推薦這樣做。但是在大多數系統中，尤其是Windows系統中，以Windows XP為例，如果設定非連續子網掩碼的話，將會出現如下提示：
不知這個能不能在Windows XP的系統說明里面能不能找到，期待ing...