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Right now, I am using internet at home, and my private ip address is 192.168.x.x.

At work my private ip address is 10.x.x.x.

In both of the scenarios, I did not play any role in selecting my ip, I just connected my machine to the network.

So, who determines what kind of ip I am going to get. Who decides whether the ip would be 10.x.x.x or 192.x.x.x. And why are there different types of private ip.

-EDIT: question has been modified based on first responses.

closed as off-topic by rnxrx, Teun Vink Jul 28 at 11:50

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "NE is a site for to ask and provide answers about professionally managed networks in a business environment. Your question falls outside the areas our community decided are on topic. Please visit the help center for more details. If you disagree with this closure, please ask on Network Engineering Meta." – rnxrx, Teun Vink
If this question can be reworded to fit the rules in the help center, please edit the question.

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    In both cases your computer uses DHCP to get an address. In the home case, this is provided by your router, and is factory programmed to use the 192.168.0.0 range. For work, it is your network administrator's decision which address range to use. – Ron Trunk Jul 25 at 19:19
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    You say the network is not under your direct control, that makes it off-topic; as does (in this case) not asking how but asking why. – Rob Jul 26 at 13:51
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Classful networking died in 1993 and was replaced by CIDR. With CIDR, any subnet prefix length is possible. You can use 192.168.0.0/16 just as well as 10.0.0.1/31 (for private addresses). Nobody stops you from using 10.0.0.0/8 at home or elsewhere.

Most often, IP address and prefix length aka network mask are assigned by a DHCP server.

[edit]

Who decides whether the ip would be 10.x.x.x or 192.x.x.x.

Your network admin does and your DHCP server distributes these addresses.

And why are there different types of private ip.

The IETF decided to allocate a range for each (former) class for private use. These ranges are defined in RFC 1918:

  • 192.168.0.0/16
  • 172.16.0.0/12
  • 10.0.0.0/8
  • I've modified the question to get my question across more clearly. – Dude Jul 25 at 19:14
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    Nobody stops you from using 10... Not a Uverse user I see. :-) They don't allow 10/8 for various bad reasons. – Ricky Beam Jul 25 at 20:36
  • And to get the historical order right: Classful networking was 3 years dead when RFC1918 defined these 3 CIDR ranges for private use. That means 10.x.x.x has never been a class-A reservation. – MSalters Jul 26 at 15:49
  • @MSalters, it was actually RFC 1597 that defined the three Private Address ranges. RFC 1918 updated that RFC and cleared up the confusion caused by RFC 1627. – Ron Maupin Jul 26 at 16:59
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What determines the class of private ip addresses?

Nothing because network classes are dead (please let them rest in peace), killed in 1993 (over 25 years ago, before the Internet went commercial!) by RFCs 1517, 1518, and 1519, which defined CIDR (Classless Inter-Domain Routing). Modern networking does not use network classes.


If you want a history lesson, this answer explains what used to define network classes.


Edit:

Your question is now completely different after you got answers for the original question. That means you should have asked in a different question. This is very bad for for SE sites.

In any case, you are free to configure any Private IPv4 addressing from any of the Private IPv4 address ranges on your own private network. There is no standard requiring any particular range on any network.

What determines the private ip addresses?

RFC 1918, Address Allocation for Private Internets defines Private IP addressing.

So, who determines what kind of ip I am going to get. Who decides whether the ip would be 10.x.x.x or 192.x.x.x.

What you have at work was configured by the network administrators, likely assigned by what is configured on a DHCP server, although it may be statically configured. What you have at home is based on how you have your equipment configured (probably just took the equipment default), most likely assign by a DHCP server in a consumer-grade router (home networking and consumer-grade equipment are explicitly off-topic here).

And why are there different types of private ip.

Back when private addressing was created (prior to CIDR), classful addressing was still common. The reasons for the three address ranges are explained in RFC 1918:

If a suitable subnetting scheme can be designed and is supported by the equipment concerned, it is advisable to use the 24-bit block (class A network) of private address space and make an addressing plan with a good growth path. If subnetting is a problem, the 16-bit block (class C networks), or the 20-bit block (class B networks) of private address space can be used.

  • I've modified the question to get my question across more clearly. – Dude Jul 25 at 19:14
  • I edited my answer, but you completely changed the question, and that is very bad form. – Ron Maupin Jul 25 at 19:17
  • I am unable to delete the question. If you can delete it, I can ask the question separately. – Dude Jul 25 at 19:19

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