6.5.1

Table Of Contents
The ESXi implementation of Kerberos for NFS 4.1 provides two security models, krb5 and krb5i, that offer
different levels of security.
n
Kerberos for authentication only (krb5) supports identity verification.
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Kerberos for authentication and data integrity (krb5i), in addition to identity verification, provides data
integrity services. These services help to protect the NFS traffic from tampering by checking data
packets for any potential modifications.
Kerberos supports cryptographic algorithms that prevent unauthorized users from gaining access to NFS
traffic. The NFS 4.1 client on ESXi attempts to use either the AES256-CTS-HMAC-SHA1-96 or AES128-
CTS-HMAC-SHA1-96 algorithm to access a share on the NAS server. Before using your NFS 4.1
datastores, make sure that AES256-CTS-HMAC-SHA1-96 or AES128-CTS-HMAC-SHA1-96 are enabled
on the NAS server.
The following table compares Kerberos security levels that ESXi supports.
Table 175. Types of Kerberos Security
ESXi 6.0 ESXi 6.5
Kerberos for authentication
only (krb5)
Integrity checksum for RPC
header
Yes with DES Yes with AES
Integrate checksum for RPC
data
No No
Kerberos for authentication and
data integrity (krb5i)
Integrity checksum for RPC
header
No krb5i Yes with AES
Integrate checksum for RPC
data
Yes with AES
When you use Kerberos authentication, the following considerations apply:
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ESXi uses Kerberos with the Active Directory domain.
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As a vSphere administrator, you specify Active Directory credentials to provide access to NFS 4.1
Kerberos datastores for an NFS user. A single set of credentials is used to access all Kerberos
datastores mounted on that host.
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When multiple ESXi hosts share the NFS 4.1 datastore, you must use the same Active Directory
credentials for all hosts that access the shared datastore. To automate the assignment process, set
the user in host profiles and apply the profile to all ESXi hosts.
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You cannot use two security mechanisms, AUTH_SYS and Kerberos, for the same NFS 4.1 datastore
shared by multiple hosts.
See the vSphere Storage documentation for step-by-step instructions.
Set Up NFS Storage Environment
You must perform several configuration steps before you mount an NFS datastore in vSphere.
vSphere Storage
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