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# Best practice Subnet 이해
VPC Subnets in 1 zone
* 과거에는 On-premise 서브넷팅을 잘게잘게 쪼개는게 맞았다 ( o )
* Because 층별로 구역별로, 부서 by 부서, 사람 by 사람으로 인터넷 방화벽 셋팅이 필요했기 때문에
* IP추적이 필요했기 때문에
Subnet by Zone
* AWS Zone 을 High Availiability를 위해 Zone 을 나누는게 중요
Private and Public subnets-1
* 과거에는 24bit 사용하는게 범용적이었다.
* Because 읽기 편하기 때문이었죠.
* C-Natative 더이상 IP를 사용하는 것보다 Security, IP대역 넣는게 아니라 SG ID를 넣는게 좋은 것이다.
Private and Public subnets-2
* Subnet을 나누는 기준은 용도별이 아니라 Routing Table 분할할때 사용하는 것이다.
* Route table 에 따라서 서브넷을 종속시키고, 구분시켜야 한다.
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