subneting .. is 192.168.0.1/24 different than 192.168.0.1/25

Posted by SM on Server Fault See other posts from Server Fault or by SM
Published on 2010-04-19T06:26:48Z Indexed on 2010/04/19 6:34 UTC
Read the original article Hit count: 1415

Filed under:

subnet

|

subnetting

So i am trying to understand subnetting. I understand that you can take 192.168.0.0/24 domain and break it up in 2 subnets. 192.168.0.0/25 and 192.168.0.128/25 .. so what if i need to create 2 more subnets inside both of those above subnets.

What if i need to create 2 subnets, which have 2 more subnets inside them and each of those 2 subnets have 2 hosts. As per my calculation, this would be something like.

top 2 subnets: 192.168.0.0/25 and 192.168.0.128/25

subnets of 192.168.0.0/25: 192.168.0.0/26 - 192.168.0.128/26

subnets of 192.168.0.128/25: 192.168.0.128/26 - 192.168.0.192/26

hosts of 192.168.0.0/25: 192.168.0.1/25 - 192.168.0.2/25

hosts of 192.168.0.128/25: 192.168.0.129/25 - 192.168.0.130/25

hosts of 192.168.0.0/26: 192.168.0.1/26 - 192.168.0.2/26

hosts of 192.168.0.128/26: 192.168.0.129/26 - 192.168.0.130/26

hosts of 192.168.0.128/26: 192.168.0.129/26 - 192.168.0.130/26

hosts of 192.168.0.192/26: 192.168.0.193/26 - 192.168.0.194/26

The above doesnt seem right, i am moving down like a tree, however the subnet mask and IPs are being repeated, i am just add 1 to /x and making the ips from there. Can anyone please tell me if this is correct

The scenario i am trying to understand is similar to this, however i just want to add hosts on each level as well. http://www.ciscotrick.com/wp-content/uploads/2008/08/the_mathematical_relationship_between_network_block_sizes.jpg

© Server Fault or respective owner

Related posts about subnet

Can I subnet a subnet?

as seen on Server Fault - Search for 'Server Fault'
Apologies in advance for the botched terminology. I have read the Server Fault Subnet Wiki but this is more of an ISP question. I currently have a /27 block of public IPs. I use give my router the first address in this pool and then use 1-to-1 NAT for all the servers behind the firewall, so that… >>> More
Connecting to a remote server through OpenVPN when local network subnet conflicts with remote network's subnet

as seen on Server Fault - Search for 'Server Fault'
After connecting to a remote location via OpenVPN, I am trying to access a server on a network that exists on a subnet such as 10.0.1.0/24. However, the network I am trying to access this remote server from is on the same subnet: 10.0.1.0/24. I am unable to connect to my remote server via typing… >>> More
How to Route Traffic in Case PPTP Remote Client is on Same Subnet as Server

as seen on Server Fault - Search for 'Server Fault'
I've a PPTP server setup on my local home network (192.168.1.0/24, pfSense). Now sometimes when I'm away and want to connect remotely my client (Windows 7) is also on the same network because e.g. the hotel has set it up the same way. Thus the connection works, but I can't reach any PC on my home… >>> More
Changing subnet-mask of class-c network host to 255.255.0.0

as seen on Server Fault - Search for 'Server Fault'
We have a existing class-c network with IP address range 11.22.33.44/24 (just for example). My domain controller has been configured within this subnet. So all servers within this subnet have subnet mask configured to 255.255.255.0. Now we have got a new subnet with IP address 11.22.88.99/24 (note… >>> More
Issues resolving DNS entries for multi-homed servers

as seen on Server Fault - Search for 'Server Fault'
This is difficult to explain, so bear with me. We have 2 domain controllers, each multi-homed to straddle 2 internal subnets, (subnet A and subnet B) and provide dns, dhcp, and ldap authentication. Both domain controllers each have 2 DNS entries. both entries have identical host names, but correspond… >>> More

Related posts about subnetting

ServerFault Wiki: How does Subnetting Work?

as seen on Server Fault - Search for 'Server Fault'
How does Subnetting Work, and How do you do it by hand or in your head? Can someone explain both conceptually and with several examples? Serverfault gets lots of subnetting homework questions, so we could use an answer to point them to on serverfault itself. If I have a network, how do I figure out… >>> More
Server Fault Wiki: How does Subnetting Work?

as seen on Server Fault - Search for 'Server Fault'
How does Subnetting Work, and How do you do it by hand or in your head? Can someone explain both conceptually and with several examples? Server Fault gets lots of subnetting homework questions, so we could use an answer to point them to on Server Fault itself. If I have a network, how do I figure out… >>> More
How does Subnetting Work?

as seen on Server Fault - Search for 'Server Fault'
How does Subnetting Work, and How do you do it by hand or in your head? Can someone explain both conceptually and with several examples? Server Fault gets lots of subnetting homework questions, so we could use an answer to point them to on Server Fault itself. What is classless routing and why… >>> More
subnetting a class c on a cisco 3825

as seen on Server Fault - Search for 'Server Fault'
I have a class C that I want to better understand before I implement a change. Right now, ip address 192.168.0.1 255.255.255.192 ip address 192.168.0.65 255.255.255.240 secondary So, where is the 192.168.0.64 address in that mix? 192.168.0.63 should be the broadcast for the first one, and 192… >>> More
Trouble subnetting...

as seen on Server Fault - Search for 'Server Fault'
I have to learn how to subnet by hand for a test. And I'm having real problems doing it. I keep getting stuck. Here's an example: 138.248.184.17/18 - IP 255.255.192.0 - Subnet Mask 192 = 1100 0000 in binary And I know 184 in the IP address is the "octet of interest". OK I get that far...and then… >>> More