From f77bfc499fb6618123e7967f52b6cf0677c7ea7a Mon Sep 17 00:00:00 2001
From: stationname <142196408+stationname@users.noreply.github.com>
Date: Mon, 29 Apr 2024 19:21:35 +0900
Subject: [PATCH] Add learning reference to CIDR (#5573)

---
 src/data/roadmaps/aws/content/102-vpc/100-cidr-blocks.md | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/data/roadmaps/aws/content/102-vpc/100-cidr-blocks.md b/src/data/roadmaps/aws/content/102-vpc/100-cidr-blocks.md
index 1efb750db..94e36d3e6 100644
--- a/src/data/roadmaps/aws/content/102-vpc/100-cidr-blocks.md
+++ b/src/data/roadmaps/aws/content/102-vpc/100-cidr-blocks.md
@@ -1,3 +1,7 @@
 # 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.
\ No newline at end of file
+"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.
+
+## References
+
+- [cidr.xyz: Interactive CIDR range visualizer](https://cidr.xyz/)