Learning Subnetting Part 3 - Dividing a Network into Subnets

I show how the process of subnetting is merely dividing a large network into smaller networks by changing the length of the subnet mask. I discuss how the number of host addresses change in subnets, subnet bits versus host bits, and ANDing to find the network address.

[lee-heey]

by far one of the best explanations I've seen to get your head around subnets. thank you.

[sagul-sagul]

Hi Dan, I have been following you before I got my CCNA. Your videos helped me a lot during my certification 3 years ago. Keep this up.

[goldenbrands]

Thanks Dan, this is the best explanation of subnetting and anding, finally makes sense

[vinaykaradia]

Thanks Dan for explaining subnets. I don't have networking background and every time, IP address comes in front of me; my mind goes blank. But with this video and some practice, I understand this. Thanks once again.

[omarquimbay]

This is the best video explaining subnetting 🎉

[mysteriousraids]

Thank you for making this video, this just made my night a million times easier.

[vv]

Hello. The best explanation I found about the topic. Thank you so much.

[jeremy]

Great video on dividing networks! very well done and explained, thanks Dan!

[Velo]

These damn computer engineers sure didn’t make this simple did they?

[Adatus]

This helped me to understand subnetting really well! Thank you! Now diving into supernetting...

[soulvitamin]

Thank you for the video I couldn't find the explanation anywhere else for me too understand

[dipendrasnkr]

It's really so easy way to learn . Thanks a lot

[thecsabel]

Thanks for the vid. Got it now. Had to understand it for uni coursework.

[LIMuscleBlackdevil]

I'm just learning this stuff now. Why would you need to alter the subnet mask for more networks when you already have 3 whole octets on the on the network side with a /24 you can alter for more networks? Is it to just make the broadcast domains smaller?

[hurleymediatv]

I watched a video prior to yours, which explained subnet masks. It was very professional, and I understood everything in it, but one thing was missing. What the actual IP addressing is used for the new split (/25) networks. I was left wondering what IP ranges, were used in order to have them be separate from each other. Your video explains it clearly. Thank you!

[BradleyHerbst]

My question is how you would handle routing? So I assume all these networks will need a default gateway. What would happen if something on the subdivided network tried to talk to overlapping IP on the un-subdivided network, ?

[SUTTy]

This is invaluable info but I'm wondering if there are any video's of this actually being done in real life using a Sonicwall or router? Any recommendations?

[bme]

I was a bit confused on how to setup multiple subnets on my one LAN to keep some devices isolated from others. Just not sure what my default gateway/router address/subnet mask should be.

[channelI]

Hi, great video - I'm looking for a Cheat sheet that tells you how many subnetworks the sub mask creates but they all just tell you how many hosts and that's it. I know you could calculate it from the number of hosts but that's not what I'm looking for.

Also seems bizarre its Subnetting sub networks and no one wants to include how many networks it sub creates???

[sxwrvkn]

I don't understand, how do you have "more subnets"? If the network portion of the IP is now /25 for example, you have 128 hosts now (minus 2). Ok. That's one network. Where's the second subnet?
edit: Nvm you explain later.