officertango
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general IP subnetting
I want to create a network that I can grow with, want to use class B (/16) subnet with network number 10.10.0.0. I need about 12 networks subnet, several subnets need more than 254 IP (say about 400 IP). Can someone give me a break down of the 12 networks for 10.10.0.0?
thanks
thanks
2^n -2 = 2^4 -2 = 14 networks
10.0.0.0/12
Cheers
SA
10.0.0.0/12
Cheers
SA
ASKER
So if I have 10.106.0.0/16, I can sub net it down to say 10.106.1.0/32 for one network and another say 10.106.2.0/255.255.254.0. Is it bad to have subnet with 510 hosts?
Thanks
Thanks
SOLUTION
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In your original post you had mentioned 10.10.0.0 and then later 10.106.0.0. I am going to go with your latest: 10.106.0.0
Minor note on Class terminology: Class B addresses are within the range : 128.0.0.0 to 191.255.255.254. A 10.106.0.0 is actually a Class A address. Your 10.106.0.0 would a subnet withing the Class A. Not important, but then again.
If you start with 10.106.0.0 and use /24 subnet mask across the board you will end up with subnets: 10.106.0.0 through 10.106.255.0 with each subnet having 254 host addresses. That's 256 subnets (counting subnet 0).
That should be your template for your network allowing you to grow as needed.
From there you can change the subnet mask to increase or decrease the number of host.
What you have to remember and make sure you have planned well is where the subnet's host addresses start and where they end.
For example:
Subnet 1 => 10.106.1.0/24 Hosts: 10.106.1.1 to 10.106.1.254 (254 addresses)
Subnet 2 => 10.106.2.0/24 Hosts: 10.106.2.1 to 10.106.2.254 (254 addresses)
Subnet 3 => 10.106.3.0/23 Hosts: 10.106.3.1 to 10.106.4.254 (510 addresses)
Subnet 4 => 10.106.5.0/24 Hosts: 10.106.5.1 to 10.106.5.254 (254 addresses)
Subnet 5 => 10.106.6.0/23 Hosts: 10.106.6.1 to 10.106.7.254 (510 addresses)
Subnet 6 => 10.106.8.0/25 Hosts: 10.106.8.1 to 10.106.8.126 (126 addresses)
Subnet 7 => 10.106.8.128/25 Hosts: 10.106.8.129 to 10.106.8.254 (126 Addresses)
Subnet 8 => 10.106.9.0/24 Hosts: 10.106.9.1 to 10.106.9.254 (254 addresses)
Next one can start at 10.106.10.0 and so on depending on the subnet mask.
Minor note on Class terminology: Class B addresses are within the range : 128.0.0.0 to 191.255.255.254. A 10.106.0.0 is actually a Class A address. Your 10.106.0.0 would a subnet withing the Class A. Not important, but then again.
If you start with 10.106.0.0 and use /24 subnet mask across the board you will end up with subnets: 10.106.0.0 through 10.106.255.0 with each subnet having 254 host addresses. That's 256 subnets (counting subnet 0).
That should be your template for your network allowing you to grow as needed.
From there you can change the subnet mask to increase or decrease the number of host.
What you have to remember and make sure you have planned well is where the subnet's host addresses start and where they end.
For example:
Subnet 1 => 10.106.1.0/24 Hosts: 10.106.1.1 to 10.106.1.254 (254 addresses)
Subnet 2 => 10.106.2.0/24 Hosts: 10.106.2.1 to 10.106.2.254 (254 addresses)
Subnet 3 => 10.106.3.0/23 Hosts: 10.106.3.1 to 10.106.4.254 (510 addresses)
Subnet 4 => 10.106.5.0/24 Hosts: 10.106.5.1 to 10.106.5.254 (254 addresses)
Subnet 5 => 10.106.6.0/23 Hosts: 10.106.6.1 to 10.106.7.254 (510 addresses)
Subnet 6 => 10.106.8.0/25 Hosts: 10.106.8.1 to 10.106.8.126 (126 addresses)
Subnet 7 => 10.106.8.128/25 Hosts: 10.106.8.129 to 10.106.8.254 (126 Addresses)
Subnet 8 => 10.106.9.0/24 Hosts: 10.106.9.1 to 10.106.9.254 (254 addresses)
Next one can start at 10.106.10.0 and so on depending on the subnet mask.
ASKER
How did you know 10.106.0.0 is class A? Should I not subnet anything greater than 254 hosts of I have layer 3 switch to route vlan.
Thanx to help me understand
Thanx to help me understand
By RFC 791 definition:
Class A 0.0.0.0 to 127.255.255.254
Class B 128.0.0.0 to 191.255.255.254
Class C 192.0.0.0 to 223.255.255.254
And, there are more Classes. See: Classful Networks
But, that does not mean you can use a 10.x.x.x however you want. You will be using it in what is known as "classless" fashion. That is perfectly fine. If you were to use a routing protocol on a Cisco router or L3 switch, you would have to specify "ip classless". So, if you are using a Cisco device (L3 switch or router) make sure that command is there even if you are not routing with a routing protocol. It should be default.
You can have as many variation as you want within the big subnet; e.g in this case 10.106.0.0, as long as you plan everything correctly and there are no overlaps. See my previous note.
You just need to plan everything on paper first and make sure the subnets start and end on the correct host IPs.
Class A 0.0.0.0 to 127.255.255.254
Class B 128.0.0.0 to 191.255.255.254
Class C 192.0.0.0 to 223.255.255.254
And, there are more Classes. See: Classful Networks
But, that does not mean you can use a 10.x.x.x however you want. You will be using it in what is known as "classless" fashion. That is perfectly fine. If you were to use a routing protocol on a Cisco router or L3 switch, you would have to specify "ip classless". So, if you are using a Cisco device (L3 switch or router) make sure that command is there even if you are not routing with a routing protocol. It should be default.
You can have as many variation as you want within the big subnet; e.g in this case 10.106.0.0, as long as you plan everything correctly and there are no overlaps. See my previous note.
You just need to plan everything on paper first and make sure the subnets start and end on the correct host IPs.
Also check out RFC 1918:
For a "Custom" Class B subnet (17-23 bit mask) you would also use subnet addresses in that range.
- Tom
http://tools.ietf.org/html
Search for "Private Address Space" and you will find the address blocks reserved for private networking.
This address space is often referred to as "non-routable" as it is NOT supposed to route on the Internet proper, just in private networks allowing these addresses to be reused by private entities (behind firewalls using Network Address Translation) conserving "public" addressing for the public (Internet) arena.
Using the above reference, you will find that for a Class B subnet (16 bit mask) you may use a subnet address template of 172.x.0.0 where x may be in the range of 16-31.Search for "Private Address Space" and you will find the address blocks reserved for private networking.
This address space is often referred to as "non-routable" as it is NOT supposed to route on the Internet proper, just in private networks allowing these addresses to be reused by private entities (behind firewalls using Network Address Translation) conserving "public" addressing for the public (Internet) arena.
For a "Custom" Class B subnet (17-23 bit mask) you would also use subnet addresses in that range.
- Tom
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Any way, a subnet mask of 255.255.254.0 will give you 510 hosts.
You can start with 10.10.0.0/23 then go to 10.10.2.0/23, then 10.10.4.0/23, continue increasing the 3rd octect by 2 until you have 12.