diff --git a/README.md b/README.md
index 087d7e5..a7dadc9 100644
--- a/README.md
+++ b/README.md
@@ -141,6 +141,7 @@ Project or files:
 │   ├── async-speed-limit
 │   ├── dingo
 │   ├── ip
+│   ├── ipnet-demo
 │   ├── iptables
 │   ├── mailsend
 │   ├── message_io
@@ -269,6 +270,6 @@ Project or files:
     ├── vec.rs
     └── while.rs
 
-238 directories, 39 files
+239 directories, 39 files
 ```
 
diff --git a/__network/ipnet-demo/Cargo.lock b/__network/ipnet-demo/Cargo.lock
new file mode 100644
index 0000000..d2cbd13
--- /dev/null
+++ b/__network/ipnet-demo/Cargo.lock
@@ -0,0 +1,16 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "ipnet"
+version = "2.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "30e22bd8629359895450b59ea7a776c850561b96a3b1d31321c1949d9e6c9146"
+
+[[package]]
+name = "ipnet-demo"
+version = "0.1.0"
+dependencies = [
+ "ipnet",
+]
diff --git a/__network/ipnet-demo/Cargo.toml b/__network/ipnet-demo/Cargo.toml
new file mode 100644
index 0000000..70aa10f
--- /dev/null
+++ b/__network/ipnet-demo/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "ipnet-demo"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+ipnet = "2.7.1"
diff --git a/__network/ipnet-demo/src/main.rs b/__network/ipnet-demo/src/main.rs
new file mode 100644
index 0000000..f335c98
--- /dev/null
+++ b/__network/ipnet-demo/src/main.rs
@@ -0,0 +1,16 @@
+use std::net::Ipv4Addr;
+use std::str::FromStr;
+use ipnet::{Ipv4Net, Ipv6Net};
+
+fn main() {
+    let net4 = Ipv4Net::from_str("10.1.1.0/24").unwrap();
+    let net6 = Ipv6Net::from_str("fd00::/24").unwrap();
+
+    println!("{:?}", net4);
+    println!("{:?}", net6);
+
+    let ip: Ipv4Addr = "192.168.0.1".parse().unwrap();
+    println!("{}", net4.contains(&ip));
+    let ip: Ipv4Addr = "10.1.1.1".parse().unwrap();
+    println!("{}", net4.contains(&ip));
+}