Suggest an editImprove this articleRefine the answer for “Why is the network layer considered "routable"?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**The network layer is considered "routable"** because it is exactly at this layer that the decision is made about which networks and devices to send data through, and it is here that delivering data between different networks becomes possible. **Key point:** only the network layer can direct data beyond a single local network.Shown above the full answer for quick recall.Answer (EN)Image**The network layer is considered "routable"** because **it is exactly at this layer that the decision is made about which networks and devices to send data through**, and it is here that **delivering data between different networks** becomes possible. Short and clear: **only the network layer can direct data beyond a single local network**. --- ## What "routable" means "Routable" means that data: - can be transmitted **through several networks** - passes through **routers** - at each stage receives a decision: - where to send the packet next This is possible **only when logical addressing and routes exist**. --- ## Why this is possible specifically at the network layer ### 1. **The presence of logical addresses (IP)** The network layer uses **IP addresses**, which: - show **network membership** - allow distinguishing "your own" network from "someone else's" - are understood identically by all routers MAC addresses do not work this way: - they are local - they carry no information about the network's structure --- ### 2. **How routers work** Routers: - operate at the **network layer (L3)** - analyze the **IP header of the packet** - use **routing tables** - choose the next hop for forwarding the packet Without the network layer, routers would be impossible. --- ### 3. **Independence from the data link layer** The network layer: - does not depend on the L2 technology (Ethernet, Wi-Fi, and so on) - can carry packets over different types of networks This allows a packet to: - pass through different data link technologies - not "break" along the way --- ### 4. **A single packet format** An IP packet: - is preserved from source to destination - is used by all routers - is forwarded regardless of the transmission medium Only these change: - data link layer frames - the physical medium --- ## What is important for an interview - routing = **L3** - **packets** are routed, not frames - IP is a routable protocol - MAC is a non-routable address --- ## In short, for an interview > **The network layer is considered routable because it uses logical IP addresses and supports route selection and the transmission of packets between different networks through routers.**For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.