CIDR Blocks
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What is CIDR Blocks?
"CIDR" stands for Classless Inter-Domain Routing. In AWS VPC, a CIDR block is the IP address block from which private IPv4 addresses and public IPv4 addresses are allocated when you create a VPC. The CIDR block can range from /28 (16 IP addresses) to /16 (65,536 IP addresses). It represents a network segment and is associated with a network boundary. Upon creation, you cannot change the CIDR block of your VPC, but you can add additional CIDR blocks to it if needed. A VPC's CIDR block should not overlap with any of the existing network's CIDR blocks.
Free resources to learn CIDR Blocks
- Official docscidr.xyz: Interactive CIDR range visualizer
- Official docsVPC - CIRD Blocks
More in stage 3: VPC
CIDR Blocks: common questions
Can I learn CIDR Blocks in Hindi?
This lesson is written in English. Once you sign in, open it in the interactive course and ask the AI tutor to explain CIDR Blocks in Hindi or Hinglish. The tutor answers from this lesson’s own text, so it stays on the syllabus, and it runs on your own Google, OpenAI or Anthropic key.
Is this CIDR Blocks tutorial for beginners?
It is lesson 18 of 101 in the free AWS roadmap, in stage 3, VPC. If you are new to AWS, start from stage 1 and come back here in order; if you already know the earlier stages, this lesson stands on its own.