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subnet mask for 10.0.0.9 ip address 1

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deebaglee

Technical User
May 16, 2003
301
GB
hi
correct me if i am wrong but an ip address of 10.0.0.9 would be classed as a class A network and have a subnet mask of 255.0.0.0 but as i ran ipconfig on a pc the subnet mask for the above mentioned ip address was 255.255.255.0
also can you explain what a node type hybrid is please

thanks
 
> 10.x.x.x is class a

Yes.

>the subnet mask for the above mentioned ip address was >255.255.255.0

So they have turned this into a class c address range or 10.0.0.x. Its a odd setup but will work - depending on how the rest of the machines are setup.

> a node type hybrid is please

Its how wins resolves. Hybrid means it tries to use a wins server, if that fails it will use its cache, lmhosts, and broadcasting.
 
thank you for your help
but i am still bathled by the fact that the subnet mask is in corresponding with the ip addres
 
> but i am still bathled by the fact that the subnet mask
> is in corresponding with the ip addres

10.x.x.x is a private address and was designed to be a class A network. That doesn't mean it has to be a class a network, it can class b, c or classless.

Their is nothing wrong with the setup, but like I said its just a little odd.



 
The subnet mask simply defines the usable range of the network. It can be used to segment a class A, B or C into smaller ranges or (super netting) combining smaller adjacent ip ranges into a larger network address (usaully done with class C addresses).

If the ip range falls within the range defined by the subnet your systems will communicate with out the need of a router or routing entry.
 
there is nothing odd about this. If an organization has an A class assigned to them they are going to subnet it into smaller managable networks. if the company did not subnet it, there would be 16,777,214 computers on one network which would be very congested and very unmanagable. In this case, your organization has subneted your network into a possible 16,777,214 networks each with 254 computers per network(i think these calculations are correct, someone might want to double check)
 
> If an organization has an A class assigned to

10.x.x.x is a private range, they haven't got any IP assigned to them

>there would be 16,777,214 computers on one network which

yes thats a lot of hosts, so why not just use 192.168 class C or use 172.16-32 class B?

10.x.x.x is almost exclusively used by large private networks, such as broadband grids. Why use 10.x.x.x when you could have 192.168.x.x ?



 
sorry thats 65536 networks with 254 computers per network
 
What if a company had more than 254 computers on its network, 300 for example. The network you provided, 192.168.x.x, only provides 254 possible computer connections.


I work for a small company and we use an A class subnetted as a class C. I decided to do thisfor two reasons:

1. potential for growth.

2. one network is for hosting servers and the other network is for "client" computers

 
to ashpp:

> If an organization has an A class assigned to
>10.x.x.x is a private range they haven't got any IP >assigned to them

the fact that it is private or not is irrelevant...that is not my point. I could have easily said:

If an organization assigns themselves a class A private address space.
 
>What if a company had more than 254 computers on its >network, 300 for example. The network you provided, >192.168.x.x, only provides 254 possible computer >connections.

Easy change the subnet mask to reflect how many hosts/networks you want.

> 1. potential for growth.

This isn't an issue unless you are a exteremely big company or are using larges wans/mans.

Anyway this is all beside the point, I said the choice was odd thats all, not wrong. IE. I don't often see that setup
 
> yes thats a lot of hosts, so why not just use 192.168 class C or use 172.16-32 class B?

I use 10.* instead of 192.168 0r 172.16-32 (for ALL private networks) because 10.* is easier to type and remember. I usually use class B or C subnets depending on the network. It really doesn't matter which private range you use as long as you have room for reasonable growth so why type more than you need to?

FredUG

 
>Easy change the subnet mask to reflect how many >hosts/networks you want.

I dont know if i understand you correctly, you mean 192.168.5.0 255.255.0.0 for example?

This could be possible but it probably is considered an invalid configuration. I dont think that is what the "framers" of the internet had in mind.

>This isn't an issue unless you are a exteremely big >company or are using larges wans/mans

We are a small company but ready for IPOon a public exchange. It is possible that "overnight" we can see a substantiall increase in employees. I used an A address so i do not have to go back and reconfigure all my computers when the time arises.
 
>I dont know if i understand you correctly, you mean >192.168.5.0 255.255.0.0 for example?

As in for example a subnet mask of 255.255.224.0 giving you 6 subnets with 8190 hosts.

>This could be possible but it probably is considered an >invalid configuration.

If 192.168.5.0, sm 255.255.0.0 is an invalid configuration then so is 10.0.0.0 with a subnet mask of 255.255.255.0.

> I dont think that is what the "framers" of the internet
> had in mind.

Probably not - that why they created three private address ranges in the 3 classes.
 
The 10. range will work fine with subnet masks from A-C. 192.168 and 172.16-32 will work with B or C class subnets.

255.0.0.0 = class a (AKA /8)
255.255.0.0 = class b (AKA /16)
255.255.255.0 = class c (AKA /24)

10. in a /24 subnet is perfect valid and usable but 192.168 with a /8 is not. Additionally, 172.16-32 is a /12 (8 class b's) and uses 255.240.0.0 even though you can use /16 or /24 if you want.


> I used an A address so i do not have to go back and reconfigure all my computers when the time arises.

10. is a class a "address" but 255.255.255.0 is a subnet/24 so you only have a class c network.

Hope that helps,

FredUG
 
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