I read that this pool:
- Means "these hosts" in "this network"
- Is used for self-identification
- Is used for broadcast messages
My questions are:
- Where exactly these addresses can be found?
- Which protocols use them?
According to RFC 5735:
So, looking at RFC 1122:
So @Spiff is right, they're used exclusively in initialization procedures before obtaining the "real" IP Address.
But later on RFC 1122 states that:
so BSDs version 4.2 actually send broadcasts to
Found another piece of info:
And here appears BSD again:
The all-zeroes address is used by clients that don't know their own address yet, such as BootP/DHCP clients that have just booted or just connected to a new network and haven't been assigned an IP address from the BootP/DHCP server yet.
I look at a lot of Ethernet LAN traffic while debugging problems, and that's the only place I can think of that I've ever seen 0.0.0.0/8 in use.
Before CIDR, IP addresses were separated into a "network" part and "host" part, for example,
For example, a host could use
Where exactly these addresses can be found?
On networked machines that are currently negotiating for actual IP addresses.
Which protocols use them?
These addresses are used temporarily during ARP probes:
Looks like it's reserved by IANA - the organisation that hands out IP addresses see 000/8 in the table. The table shows 000/8 to 255/8 that's 0.0.0.0/8 to 255.0.0.0/8
I think in Windows if ipconfig shows it, it means no ip address assigned, like ipconfig /release might or would cause it.
and in netstat -n whether it's 0.0.0.0 listed as Listening or a private address from RFC 1918 like 192.168.1.0 or if it's 127/8 they tell you who can connect, so if 0.0.0.0 then anybody, if 192.168.1.0 then only them, and if 127/8 then only local host.
As to what protocol, all I can say is IP since they're IP Addresses. But maybe some higher layer protocols do.. It's not for broadcasts. And it wouldn't identify any more than any othe ip adress or network, infact less since a computer on a network shouldn't have that IP address.
In windows when a computer has that IP it is not on a network. (correction, it would be on a network if there's a wired or wireless connection, and as grawity points out, they'd still have their MAC addresses)