Suggest an editImprove this articleRefine the answer for “What tasks does the network layer solve?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**The network layer (L3)** solves tasks related to delivering data between different networks, not just between neighboring devices. **Key point:** if data needs to be transmitted outside a single local network, the network layer is responsible for that.Shown above the full answer for quick recall.Answer (EN)Image**The network layer (L3)** solves tasks related to **delivering data between different networks**, not just between neighboring devices. Put simply: **if data needs to be delivered "outside a single local network", the network layer is responsible for that**. --- ## Main tasks of the network layer ### 1. **Logical addressing** The network layer uses **IP addresses**. It is responsible for: - assigning addresses to devices - understanding **which network the destination is in** - distinguishing "this is my network or a foreign one" Without logical addressing: - the Internet simply could not exist --- ### 2. **Routing** One of the key tasks. The network layer: - determines **which routers to send data through** - chooses the path from source to destination - can change the route if part of the network is unavailable This is handled by: - routers - routing tables - routing protocols --- ### 3. **Transmitting packets between networks** At the network layer, data exists as **packets**. It: - receives data from the transport layer - packs it into IP packets - passes packets further, from network to network --- ### 4. **Determining the next hop** For each packet, the network layer decides: - **where to send it next, right now** - which next router to use Important: - the decision is made **at each router** - separately for each packet --- ### 5. **Fragmentation and reassembly of packets** If a packet is too large: - it can be **split into parts (fragmented)** - transmitted across the network - reassembled at the destination This is needed to work with networks that have different packet size limits. --- ## What the network layer does NOT do Important for an interview The network layer: - does not use MAC addresses - does not guarantee packet delivery - does not correct errors - does not control delivery order This is handled by: - the data link layer (MAC, frames) - the transport layer (TCP/UDP) --- ## Short comparison for understanding - **L2 (data link)** - delivery within a single network - **L3 (network)** - delivery between networks - **L4 (transport)** - reliability and transmission control --- ## In short, for an interview > **The network layer solves tasks of logical addressing, routing, and transmitting packets between different networks, determining the path data takes from source to destination.**For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.