diff --git a/.obsidian/workspace b/.obsidian/workspace
index 18d944e..eac7b51 100644
--- a/.obsidian/workspace
+++ b/.obsidian/workspace
@@ -9,7 +9,7 @@
         "state": {
           "type": "markdown",
           "state": {
-            "file": "School/Analyse/Layers/3. Network Layer.md",
+            "file": "School/Analyse/IPV4.md",
             "mode": "source"
           }
         }
@@ -68,7 +68,7 @@
             "state": {
               "type": "backlink",
               "state": {
-                "file": "School/Analyse/Layers/3. Network Layer.md",
+                "file": "School/Analyse/IPV4.md",
                 "collapseAll": false,
                 "extraContext": false,
                 "sortOrder": "alphabetical",
@@ -87,6 +87,7 @@
   },
   "active": "bc6e8ad9aa0f44c3",
   "lastOpenFiles": [
+    "School/Analyse/IPV4.md",
     "School/Analyse/Layers/3. Network Layer.md",
     "School/Analyse/Network Hardware.md",
     "School/Analyse/Computer Networks.md",
@@ -95,7 +96,6 @@
     "School/Analyse/Network Types.md",
     "School/Analyse/Network Software.md",
     "School/Analyse/Images/distortion.png",
-    "School/Analyse/Images/noise-signal.png",
-    "README.md"
+    "School/Analyse/Images/noise-signal.png"
   ]
 }
\ No newline at end of file
diff --git a/School/Analyse/IPV4.md b/School/Analyse/IPV4.md
new file mode 100644
index 0000000..0d4b6de
--- /dev/null
+++ b/School/Analyse/IPV4.md
@@ -0,0 +1,9 @@
+# Internet protocol Version 4 (IPV4)
+
+- IP is the principal communications protocol in the network layer.
+- IP has the task of delivering packets from source host to destination host based on IP addresses.
+
+IP defines datagram structure that encapsulate the data to be delivered.
+
+An IP datagram 
+