Arpa.mesa
Copyright © 1986 by Xerox Corporation. All rights reserved.
Hal Murray, April 5, 1986 4:22:42 pm PST
Arpa IP (Internet Protocol) Addresses are a combination of net and host numbers. There are 3 cases.
If the first bit is a 0, the next 7 are a type A net number, and the remaining 24 are the host number within that net.
If the first two bits are 10, the next 14 are a type B net number, and the remaining 16 are the host number within that net.
If the first two bits are 11, the next 22 are a type C net number, and the remaining 8 are the host number within that net.
Arpa: CEDAR DEFINITIONS = {
BYTE: TYPE = [0..100H);
Addressing
Address: TYPE = RECORD [a, b, c, d: BYTE];
nullAddress: Address = [0, 0, 0, 0];
Net: TYPE = {a, b, c};
netMasks: ARRAY Net OF Address = [
a: [0FF, 0, 0, 0],
b: [0FF, 0FFH, 0, 0],
c: [0FF, 0FFH, 0FFH, 0] ];
NetType: PROC [address: Address] RETURNS [Net];
NetNumber: PROC [address: Address] RETURNS [Address];
}.