> For the complete documentation index, see [llms.txt](https://krjaeh0.gitbook.io/j-log/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://krjaeh0.gitbook.io/j-log/network/ip-addressing-and-nat/cidr.md).

# CIDR

* [관련 자료](https://ko.wikipedia.org/wiki/CIDR)

서브넷 마스크를 축약해 표현하는 방법:

* 255.255.255.0 -> 각 옥텟을 8비트로 보고, 켜진(1) 비트 수를 합산
  * 255 = 8비트(11111111)
  * 255 = 8비트
  * 255 = 8비트
  * 0 = 0비트
  * 합계 = 8 + 8 + 8 + 0 = 24

예:

* 192.168.9.11/24 = 192.168.9.11 255.255.255.0

{% hint style="info" %}
"/24"처럼 슬래시 뒤의 숫자는 네트워크 마스크에서 1로 설정된 비트의 총 개수를 의미합니다. 이 표기법을 CIDR(Classless Inter-Domain Routing) 표기법이라고 합니다.
{% endhint %}


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