active directory like service in linux
I understand that active directory service in windows allows users to access network wide resources irrespective of their geographic locations.
I am unaware of how it is done in linux. I read some articles on ldap which say that they are used for building "a centralized repository of e-mail addresses", but my problem is that,
our organisation has 2 linux servers at different geograhic locations and it is needed that users can access any one of the linux servers from any place. i.e, it shouldn't matter where their account is created... but, their account information should be "replicated" at both the locations. how is this done? does ldap play a part in this?
Please give me some basic "clues" to pick up from.