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To fully comprehend the implementation of a multi-protocol model, it is crucial to understand how user access and file permissions are handled in a legacy single-protocol environment.
Conventionally, legacy single-protocol environments supported either a Microsoft Windows or Linux architecture. In these environments, a clear separation of protocol and authentication existed. Microsoft users authenticated with Active Directory, while Linux users authenticated with LDAP. Microsoft users accessed files through CIFS or SMB and Linux users through NFS. In a single-protocol environment, cross-platform access was not an option because Microsoft users would not access files created through NFS and vice versa, as illustrated in the following figure:
Figure 1. Legacy single-protocol environments