subnet question

[crackn101]

Hey Everyone.
I was asked to look at someones network and found
that they are using
class A network ip addresses ( 10.xx.xx.xx )
with a class C subnet. 255.255.255.0
It's a small network, 1 server and about 10 pcs.
I realize that a class A network should use 255.0.0.0
as the subnet mask,
other than being non-standard, are there any performance
reasons for going in and changing the all of subnet address
back to standard ?
TIA

 

[bf0x]

Whos to say this is not non-standard. He took a class A subnet and made it a class C classless subnet. No problems there. There are no problems as long as he keeps those IP's inside his LAN and it does not advertise to the outside.

So for example he took 10.0.0.0 and made it a class C network with a /24

That would give him 1 subnet with 256 nodes per subnet.

Network Address would be 10.0.0.0 and broadcast address would be 10.0.0.255

all available IP's would be between 10.0.0.1 - 10.0.0.254

 

[Lundah]

This is pretty common. 10.xxx.xxx.xxx is private IP address space anyway, per some RFC that I can't remember offhand. Enterprises do this all the time with private/firewalled IP networks. The advantage is that you have the whole 10.xxx class A address space to work with, so by subnetting this you can have many large subnets without worrying about running out of address space.

 

[CobolKid]

Rfc 1918; "Address Allocation for Private Internets.

 

[bcastner]

... are there any performance
reasons for going in and changing the all of subnet address
back to standard ?"

No, there are not.

 

[crackn101]

That's cool.
Thanks to all for such a quick response.
I wasn't completely sure, so that's why i asked.