How are UUIDs generated?
The DCE AES specifies the method for generating UUIDs, in case you want the gory details. In short, the UUID is a combination of the network address and current time at the moment and place it was generated. Assuming that network addresses are unique and that time never runs backwards, this guarantees that UUIDs really are unique. Some implementations of uuidgen use the hardware address of the ethernet adapter, some use the IP address of the host. It is possible to run uuidgen on machines without any network connection. In this case, the host must be assigned an address. The AES specifies a file that can hold the network address. The code for generating UUIDs is part of the publically available DCE source code. See Q 3.05: for information on obtaining the code.
