diff --git a/School/Analyse/Layers/3. Network Layer.md b/School/Analyse/Layers/3. Network Layer.md
index 8b58936..f10e581 100644
--- a/School/Analyse/Layers/3. Network Layer.md	
+++ b/School/Analyse/Layers/3. Network Layer.md	
@@ -6,4 +6,15 @@ The Network Layer breaks up segments from the Transport layer into smaller chunk
 Furthermore the Network Layer also finds the optimal path to travel from origin network to the destination network. This is called routing.
 
 ## Routing
-Routing is finding the shortest (most efficient) path from source to destination
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+Routing is finding the shortest (most efficient) path from source to destination and forwarding the messages over that calculated path.
+
+Routing is difficult because it has to deal with a lot of things:
+- Network topology may change.
+- New hosts may be added.
+- Some connections/hosts may be removed.
+- Distance between hosts may change.
+
+Routers use tables called routing tables. The table contains the next point on the shortest path to each destination.
+
+Steps:
+1. Fud
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