Suggest an editImprove this articleRefine the answer for “How does a mask separate the network from the host?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**A subnet mask separates the network from the host using a bitwise comparison (logical AND)** - it literally "tells" which bits of the IP address belong to the network and which belong to the device. **Key point:** where the mask has 1, that is the network; where it has 0, that is the host.Shown above the full answer for quick recall.Answer (EN)Image**A subnet mask separates the network from the host using a bitwise comparison (logical AND)** - it literally "tells" **which bits of the IP address belong to the network and which belong to the device**. More simply: **where the mask has 1, that is the network; where it has 0, that is the host**. --- ## How this works step by step ### 1. A mask is a set of 1s and 0s - **1** → the bit belongs to the **network** - **0** → the bit belongs to the **host** Example mask: ``` 255.255.255.0 ``` In binary form: ``` 11111111.11111111.11111111.00000000 ``` --- ### 2. An IP address is also translated into bits IP address: ``` 192.168.1.10 ``` In binary form: ``` 11000000.10101000.00000001.00001010 ``` --- ### 3. The AND operation is applied The AND rule: - 1 AND 1 = 1 - 1 AND 0 = 0 - 0 AND 0 = 0 We apply the mask to the IP: ``` IP: 11000000.10101000.00000001.00001010 Mask: 11111111.11111111.11111111.00000000 ------------------------------------------ Result 11000000.10101000.00000001.00000000 ``` Result: ``` 192.168.1.0 ``` This is the **network address**. --- ## What we got - **Network part**: ``` 192.168.1 ``` - **Host part**: ``` .10 ``` The mask: - "cut off" the host part - left only the network --- ## The main rule to remember - **IP + mask = network** - same network → devices can communicate directly - different network → a router is needed --- ## Why this matters in practice A mask lets a device understand: - whether the destination is **on the same network** - or whether the packet needs to be sent to the **gateway (router)** Without this: - normal routing would be impossible - the network simply would not work --- ## In short, for an interview > **A subnet mask separates the network from the host by marking network bits with ones and host bits with zeros; a bitwise AND with the IP address lets you extract the network address.**For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.