Chapter 27. Authentication
Configuration
When a user logs in to a Red Hat Enterprise Linux system, the
username and password combination must be verified, or authenticated, as a valid and active user.
Sometimes the information to verify the user is located on the
local system, and other times the system defers the authentication
to a user database on a remote system.
The Authentication Configuration Tool
provides a graphical interface for configuring NIS, LDAP, and
Hesiod to retrieve user information as well as for configuring
LDAP, Kerberos, and SMB as authentication protocols.
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Note |
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If you configured a medium or high security level during
installation or with the Security Level
Configuration Tool, network authentication methods, including
NIS and LDAP, are not allowed through the firewall.
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This chapter does not explain each of the different
authentication types in detail. Instead, it explains how to use the
Authentication Configuration Tool to
configure them. For more information about the specific
authentication types, refer to the Red Hat
Enterprise Linux Reference Guide.
To start the graphical version of the Authentication Configuration Tool from the
desktop, select the (on the
Panel) => =>
or type the command
system-config-authentication at a shell
prompt (for example, in an XTerm or a
GNOME terminal). To start the text-based
version, type the command authconfig as
root at a shell prompt.
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Important |
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After exiting the authentication program, the changes made take
effect immediately.
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The User Information tab has several
options. To enable an option, click the empty checkbox beside it.
To disable an option, click the checkbox beside it to clear the
checkbox. Click OK to exit the program and
apply the changes.
The following list explains what each option configures:
-
Enable NIS Support — Select this
option to configure the system as an NIS client which connects to
an NIS server for user and password authentication. Click the
Configure NIS button to specify the NIS
domain and NIS server. If the NIS server is not specified, the
daemon attempts to find it via broadcast.
The ypbind package must be installed
for this option to work. If NIS support is enabled, the portmap and ypbind services
are started and are also enabled to start at boot time.
-
Enable LDAP Support — Select this
option to configure the system to retrieve user information via
LDAP. Click the Configure LDAP button to
specify the LDAP Search Base DN and
LDAP Server. If Use TLS
to encrypt connections is selected, Transport Layer Security is
used to encrypt passwords sent to the LDAP server.
The openldap-clients package must be
installed for this option to work.
For more information about LDAP, refer to the Red Hat Enterprise Linux Reference Guide.
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Enable Hesiod Support — Select
this option to configure the system to retrieve information from a
remote Hesiod database, including user information.
The hesiod package must be
installed.
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Winbind — Select this option to
configure the system to connect to a Windows Active Directory or a
Windows domain controller. User information can be accessed, as
well as server authentication options can be configured.
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Cache User Information — Select
this option to enable the name service cache daemon (nscd) and configure it to start at boot time.
The nscd package must be installed for
this option to work.
