Score:0

Why does 10.0.0.0/8 private IPV4 address have a default network mask of 10.0.0.0/24?

ck flag
$ ifconfig
eno1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.0.0.201  netmask 255.255.255.0  broadcast 10.0.0.255
…

The mask means that only the final 8 bits of the address are available for this private network (10.0.0.0/24).

Wikipedia says that this reserved IP address is (10.0.0.0/8), and so it could instead have a netmask of 255.0.0.0.

It seems it would be convenient to be able to use a larger address space for better organization, such as:

10.0.2.* DHCP
10.0.3.* Desktops
10.0.4.* Laptops
10.0.5.* Mobiles
10.0.6.* Printers
10.0.7.* Cameras
etc.

How difficult would it be change a network to this kind of setup?
(And possibly, since the default configuration restricts this to ~256 addresses within the network rather than allowing all 3 bytes, why would it be a bad idea to do so?)

Doug Smythies avatar
gn flag
It should not be difficult to change the netmask. You can achieve your example with 255.255.248.0. It is a bad idea to do so because of the memory requirements for a DHCP server for 255.0.0.0. I tested memory needs verses bit mask years ago. If I can find the information I'll write an answer. see [here](https://ubuntuforums.org/showthread.php?t=2150970)
mangohost

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.