What is host/computer SID in Windows AD? and what is needed to identify the elements of network with it? [closed]

Question

SID as http://en.wikipedia.org/wiki/Security_Identifier

1) Help me to clarify the concept of computer SID on hypothetical situation:

suppose, I want to secure a network cable (for ex., from a workstation to the nearest switcher).

What should I minimally add to this cable in order to enable it security identifiable with SID:

• RAM?
• HDD (hard disk)?
• CPU?
• Operating system?

2) Having a Windows XP machine joined to AD domain, will a parallel (multiboot) installation of a second Windows XP bring to machine the same host/computer SID or a new one?

3) If I use an image copy of hard disk (or hard disk) with Windows XP Pro from computer A to boot from computer B, with which computer SID - of PC A or of PC B - such booted Windows XP be identified by domain controller?

Answer 1

You misunderstand how the SID is generated in Windows. There are two parts to the SID. One part is domain dependent, the second part is a generated value and is unique to that workstation. The generation process does not include any hardware inputs, it is simply a random number. It is created during the install process, and stored in the registry. When it is domained, it gets a domain SID, which is the combination of the Domain's SID and the local machine's SID.

1: That is not how the SID works in windows. The SID belongs to the workstation only.

2: Assuming both XP installs were created through the normal install process, each parallel installation will have a unique SID. As far as AD is concerned, you have two machines on your workstation.

3: If PC B was created as an exact copy of PC A, the two will share a SID. There was a single install process where the SID was created and the registry populated. The Registry was copied as part of the imaging process. The Domain Controller will identify them as the same machine (mostly, but explaining would take a lot more text).

Users also have a SID, but that's not needed for this discussion.

Answer 2

Thanks, this is helpful answer but it does not answer in any way my main (first) question (as well as the topic in the title).

Let me note that I usually write one question per post. The first one is the main, the following ones are just illustrative, explaining or collateral to the main (first) question.

1) What are the minimum hardware and software requirements needed for an element of network to be security identifiable (to have SID)? to join AD?

• (*) sysadmin138 wrote: "it [SID] is created during install process"

2) Does it (*) mean that computers running Windows but without hard disks cannot be identified or joined to AD?

2a) that installing by copying pre-installed Windows XP image makes machine unidentifiable (having the same SID)?

I frequently see that sysadmins install computers by copying images of pre-installed Windows XP from one hard disk to all new computers from the box. Does it, in comparison with (*), mean that they all (multiple computers) have the same computer SID? or that such time-saving shortcut cannot be used in network?

I myself do it in home network PCs, this one from which I am currently writing.

One can read that in MS docs Computers in Active Directory Domain that: *

(**) "The server uses the MAC address or the client machine GUID to find the computer object in Active Directory domain for each client"

3) Does it(**) mean that computer can be identifiable by MAC and make part of AD without having any SID, from question 2)?