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This explains the reason private ranges were designated but not why 192.168.0.0 in particular within the Class C range was designated to be private. Does anyone

This explains the reason private ranges were designated but not why 192.168.0.0 in particular within the Class C range was designated to be private. Does anyone know why that number in particular was chosen?

voltagex_ 8y ago
It may be lost to history - it's defined in https://tools.ietf.org/html/rfc1918#section-3 https://tools.ietf.org/html/rfc1918#section-3. I wonder if the people involved in the document are still around to ask.
- dsr_ 8y ago
  Yes, many of them are still alive and even still working in the field. Some have blogs.
IncRnd 8y ago
192.168 = 11000000 10101000 Other than the class portion of the addressing, this is no more significant than when engineers use A5 and 5A for markers (1010 0101 0101 1010). Or, so it would seem. :)
egwynn 8y ago
Found this link in one of the responses on that page: https://superuser.com/questions/784978/why-did-the-ietf-specifically-choose-192-168-16-to-be-a-private-ip-address-class https://superuser.com/questions/784978/why-did-the-ietf-spec... Similarly, I expect Postel picked 192.168 because, at the time he made the choice, it was the next available, or nearly the next available, network to be assigned from the former Class C space. This probably can't be proved one way or the other, but the pace of address assignments shown in the RFCs strongly suggests that they would have been in this general vicinity around 1993-1994 when the assignments were made. (Addresses in 192.159 were being assigned in 1992. No dates are available for assignments in 192.160-192.167 as these were at some point reallocated to RIPE.)
- danpat 8y ago
  To be clear, the 192 part is the lowest "Class C" network prefix. The 168 part was the arbitrary time-dependent part from the allocation database.
  - egwynn 8y ago
    Correct, thanks for making that explicit.
- WalterGR 8y ago
  Text formatted as code on HN is very difficult to read when on mobile. Using italics or > to quote things is better. Similarly, I expect Postel picked 192.168 because, at the time he made the choice, it was the next available, or nearly the next available, network to be assigned from the former Class C space. This probably can't be proved one way or the other, but the pace of address assignments shown in the RFCs strongly suggests that they would have been in this general vicinity around 1993-1994 when the assignments were made. (Addresses in 192.159 were being assigned in 1992. No dates are available for assignments in 192.160-192.167 as these were at some point reallocated to RIPE.)

voltagex_ 8y ago

It may be lost to history - it's defined in https://tools.ietf.org/html/rfc1918#section-3 https://tools.ietf.org/html/rfc1918#section-3. I wonder if the people involved in the document are still around to ask.

dsr_ 8y ago
Yes, many of them are still alive and even still working in the field. Some have blogs.

IncRnd 8y ago

192.168 = 11000000 10101000 Other than the class portion of the addressing, this is no more significant than when engineers use A5 and 5A for markers (1010 0101 0101 1010). Or, so it would seem. :)

egwynn 8y ago

Found this link in one of the responses on that page: https://superuser.com/questions/784978/why-did-the-ietf-specifically-choose-192-168-16-to-be-a-private-ip-address-class https://superuser.com/questions/784978/why-did-the-ietf-spec... Similarly, I expect Postel picked 192.168 because, at the time he made the choice, it was the next available, or nearly the next available, network to be assigned from the former Class C space. This probably can't be proved one way or the other, but the pace of address assignments shown in the RFCs strongly suggests that they would have been in this general vicinity around 1993-1994 when the assignments were made. (Addresses in 192.159 were being assigned in 1992. No dates are available for assignments in 192.160-192.167 as these were at some point reallocated to RIPE.)

danpat 8y ago
To be clear, the 192 part is the lowest "Class C" network prefix. The 168 part was the arbitrary time-dependent part from the allocation database.
- egwynn 8y ago
  Correct, thanks for making that explicit.
WalterGR 8y ago
Text formatted as code on HN is very difficult to read when on mobile. Using italics or > to quote things is better. Similarly, I expect Postel picked 192.168 because, at the time he made the choice, it was the next available, or nearly the next available, network to be assigned from the former Class C space. This probably can't be proved one way or the other, but the pace of address assignments shown in the RFCs strongly suggests that they would have been in this general vicinity around 1993-1994 when the assignments were made. (Addresses in 192.159 were being assigned in 1992. No dates are available for assignments in 192.160-192.167 as these were at some point reallocated to RIPE.)