and I doubt they go to all that trouble. However, it isn't practical to use logon names that are longer than 64 characters.

[Select Rating] Request or Create a KB Article » × Leave a Comment. A Microsoft Windows NT version 4.0 or earlier logon name is given to all accounts, which by default is set to the first 20 characters of the Windows 2000 logon name. Feedback submitted. This ServerFault answer states 104 characters which sounds more reasonable: I probably will create another test user to see if will work. Today i recieved request to create a user whose name is 25 character long but due to 20 charaacter limit of SAM-Account-Name i could not create it. Spelling is all correct Tim.

This limit is due to the size of the global relative identifier (RID) pool of 30 bits that makes each SID (that is assigned to user, group, and computer accounts) in a domain unique. The maximum path length is 259, for example the user Desktop folder on an English system is C:\Users\[User]\Desktop which leaves at most 241 characters for the user name. Logon names can be up to 104 characters. Her REGULAR username is 21 characters...and that is the one that should be working in any Active Directory newer than Windows 2000. Active Directory - UPN's greater than 20 characters cannot login Jan 08, 2009 09:21 PM | tobbylee1 | LINK I have an .Net 2.0 app using integrated windows authentication where Active Directory Accounts can be created through the web interface.

I will let you know the results.

There is a limit of approximately 1 billion security identifiers (SIDs) over the life of a domain. Brian, I know that pre-windows 2000 names can only be 20 characters. I suppose they could trim it but then they have to handle collisions etc. Den UPN kann man sogar bei Migrationen beibehalten und auch an aktuelle Namen anpassen, ohne dass Profil, Berechtigungen o.ä.

The actual limit is 230 or 1,073,741,823 RIDs. verloren gehen würden. Active Directory Maximum Limits. I dont have any system or server running on pre 2000 OS and my Active Directory is also running on 2003 standard edition SP2 which should allow 256 character in SAM-Account-Name. Was this article helpful? For more information, see SAM-Account-Name Attribute.

Oh, and the Pre-2000 logon name is limited to 20 characters. However, for backward compatibility the limit is 20 characters. But the quick answer is 64 characters for display names and 104 characters for user logon names, however Microsoft recommends that user logon names be kept to 64 characters as well. Additional Information. UPN Suffix und Mailadresse können gleich sein Der UPNSuffix ist nicht an den Namen des Active Directory oder die Domäne gebunden, sondern kann ziemlich frei vergeben werden. That is the login user name that is working.