Hello,
Thank you for posting in Q&A forum.
If there are computers with the same SID in the same LAN that are not in the domain, it may cause network conflicts and affect the access and use of network resources, etc. However, in a domain-based environment, duplicate SIDs are not a problem because domain accounts have SIDs based on the domain SID. You can refer to the following links:
https://learn.microsoft.com/en-us/sysinternals/downloads/newsid
I hope the information above is helpful.
Best regards
Zunhui
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