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Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
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Chapter 7 Configuring Switch-Based Authentication
Controlling Switch Access with Kerberos
Table 7-5
Kerberos Terms
Term
Definition
Authentication
A process by which a user or service identifies itself to another service.
For example, a client can authenticate to a switch or a switch can
authenticate to another switch.
Authorization
A means by which the switch identifies what privileges the user has in a
network or on the switch and what actions the user can perform.
Credential
A general term that refers to authentication tickets, such as TGTs
1
and
service credentials. Kerberos credentials verify the identity of a user or
service. If a network service decides to trust the Kerberos server that
issued a ticket, it can be used in place of re-entering a username and
password. Credentials have a default lifespan of eight hours.
Instance
An authorization level label for Kerberos principals. Most Kerberos
principals are of the form
user@REALM
(for example,
[email protected]). A Kerberos principal with a Kerberos
instance has the form
user/instance@REALM
(for example,
smith/[email protected]). The Kerberos instance can be used to
specify the authorization level for the user if authentication is successful.
The server of each network service might implement and enforce the
authorization mappings of Kerberos instances but is not required to do so.
Note
The Kerberos principal and instance names
must
be in all
lowercase characters. The Kerberos realm name
must
be in all
uppercase characters.
KDC
2
Key distribution center that consists of a Kerberos server and database
program that is running on a network host.
Kerberized
A term that describes applications and services that have been modified
to support the Kerberos credential infrastructure.
Kerberos realm
A domain consisting of users, hosts, and network services that are
registered to a Kerberos server. The Kerberos server is trusted to verify
the identity of a user or network service to another user or network
service.
Note
The Kerberos realm name
must
be in all uppercase characters.
Kerberos server
A daemon that is running on a network host. Users and network services
register their identity with the Kerberos server. Network services query
the Kerberos server to authenticate to other network services.
KEYTAB
3
A password that a network service shares with the KDC. In Kerberos 5
and later Kerberos versions, the network service authenticates an
encrypted service credential by using the KEYTAB to decrypt it. In
Kerberos versions earlier than Kerberos 5, KEYTAB is referred to as
SRVTAB
4
.
