Suggest an editImprove this articleRefine the answer for “What is a subnet?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**A subnet** is a logically separated part of an IP network, created using a subnet mask, that defines its own range of IP addresses. **Key point:** a subnet is a "part of a network" that has its own network address, range of hosts, and broadcast address.Shown above the full answer for quick recall.Answer (EN)Image**A subnet** is a **logically separated part of an IP network**, created using a **subnet mask**, that defines its own range of IP addresses. Short and clear: **a subnet is a "part of a network" that has its own network address, range of hosts, and broadcast address**. --- ## What "dividing a network into subnets" means Initially there is one network. Using a mask, it can be **split into several smaller networks**: subnets. Each subnet has: - a **network address** - **host addresses** - a **broadcast address** - its **own mask (or prefix)** --- ## Example (IPv4) There is a network: ``` 192.168.1.0/24 ``` If you split it into `/26` subnets, you get: - `192.168.1.0/26` - `192.168.1.64/26` - `192.168.1.128/26` - `192.168.1.192/26` Each of them is: - a separate subnet - a separate broadcast domain - a separate range of IP addresses --- ## Why subnets are needed Subnets are used for: ### 1. **Reducing broadcast traffic** - broadcast is limited to the subnet - the network works more stably and faster --- ### 2. **Logically dividing the network** - different departments - different network segments - different access levels --- ### 3. **Convenient routing** Routers operate: - not on individual IPs - but on **subnets (network addresses + mask)** --- ### 4. **Saving IP addresses** - addresses are allocated more rationally - there are no "empty" ranges --- ## Important points for an interview - a subnet is defined by an **IP address + mask** - different subnets: - do not exchange data directly - require a router - each subnet is a **separate broadcast domain** --- ## In short, for an interview > **A subnet** is a logically separated part of an IP network, defined by a network address and a subnet mask, which has its own range of IP addresses and is used to divide a network and simplify routing.For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.