红帽全球峰会2.2. The AUTH_SYS authentication method
The AUTH_SYS method, which is also known as AUTH_UNIX, is a client authentication mechanism. With AUTH_SYS, the client sends the User ID (UID) and Group ID (GID) of the user to the server to verify its identity and permissions when accessing files.
It is considered less secure as it relies on the client-provided information, making it susceptible to unauthorized access if misconfigured.
Mapping mechanisms ensure that NFS clients can access files with the appropriate permissions on the server, even if the UID and GID assignments differ between systems. UIDs and GIDs are mapped between NFS client and server by the following mechanisms:
- Direct mapping
UIDs and GIDs are directly mapped by NFS servers and clients between local and remote systems. This requires consistent UID and GID assignments across all systems participating in NFS file sharing. For example, a user with UID 1000 on a client can only access the files on a share that a user with UID 1000 on the server has access to.
For a simplified ID management in an NFS environment, administrators often rely on centralized services, such as LDAP or Network Information Service (NIS) to manage UID and GID mappings across multiple systems.
- User and Group ID mapping
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NFS servers and clients can use the
idmapdservice to translate UIDs and GIDs between different systems for consistent identification and permission assignment.
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