Suggest an editImprove this articleRefine the answer for “What types of addresses are used at the network layer?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)At the **network layer (L3)**, **logical addresses** are used, which allow data to be delivered between different networks and do not depend on a specific device or cable. **Key point:** the network layer uses IP addresses, which can be unicast, multicast, and (in IPv4) broadcast.Shown above the full answer for quick recall.Answer (EN)ImageAt the **network layer (L3)**, **logical addresses** are used, which allow data to be delivered **between different networks**. These addresses **do not depend on a specific device or cable** and can change. Short version: **the network layer uses IP addresses**. --- ## The main address type: IP addresses ### 1. **IPv4 addresses** The most common option. - length: **32 bits** - notation: four numbers from 0 to 255 Example: ``` 192.168.1.10 ``` An IPv4 address consists of: - a **network part** - a **host (device) part** From this address, routers understand: - which network the destination is in - where to forward the packet next --- ### 2. **IPv6 addresses** A new standard created because of IPv4 exhaustion. - length: **128 bits** - hexadecimal notation Example: ``` 2001:0db8:85a3::8a2e:0370:7334 ``` IPv6: - supports a huge number of addresses - is actively used in modern networks and the Internet --- ## Types of IP addresses by delivery method At the network layer, addresses differ **by who the data is intended for**. --- ### 1. **Unicast address** - the address of **one specific device** - the most frequent option Used when: - a packet needs to be delivered **to one recipient** --- ### 2. **Multicast address** - the address of **a group of devices** - only those subscribed to the group receive the packet Used for: - streaming video - service network protocols --- ### 3. **Broadcast address** *(IPv4 only)* - the packet is sent **to all devices in the network** - used for service tasks Important: - broadcast **is not routed** - it exists only within a single network IPv6 **has no broadcast**; multicast is used instead. --- ## Public and private IP addresses ### Private Used inside local networks: - `192.168.0.0/16` - `10.0.0.0/8` - `172.16.0.0/12` Not routed directly to the Internet. --- ### Public - unique on the Internet - used to access external resources --- ## What is important for an interview - the network layer uses **IP addresses**, not MAC - an IP address: - is logical - can change - a MAC address: - is physical - is used by the layer below (L2) --- ## In short, for an interview > **The network layer uses logical IP addresses (IPv4 and IPv6), which can be unicast, multicast, and (in IPv4) broadcast, and serve to deliver packets between networks.**For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.