Kerberos Operation - Cisco 3032 Software Configuration Manual

Controlling Switch Access with Kerberos
Table 7-5
Term
Principal
Service credential
SRVTAB
TGT
1. TGT = ticket granting ticket
2. KDC = key distribution center
3. KEYTAB = key table
4. SRVTAB = server table

Kerberos Operation

A Kerberos server can be a switch that is configured as a network security server and that can
authenticate remote users by using the Kerberos protocol. Although you can customize Kerberos in a
number of ways, remote users attempting to access network services must pass through three layers of
security before they can access network services.
To authenticate to network services by using a switch as a Kerberos server, remote users must follow
these steps:
1.
2.
3.
Authenticating to a Boundary Switch
This section describes the first layer of security through which a remote user must pass. The user must
first authenticate to the boundary switch. This process then occurs:
1.
2.
3.
4.
Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
7-42
Kerberos Terms (continued)
Definition
Also known as a Kerberos identity, this is who you are or what a service
is according to the Kerberos server.
Note
A credential for a network service. When issued from the KDC, this
credential is encrypted with the password shared by the network service
and the KDC. The password is also shared with the user TGT.
A password that a network service shares with the KDC. In Kerberos 5
or later Kerberos versions, SRVTAB is referred to as KEYTAB.
Ticket granting ticket that is a credential that the KDC issues to
authenticated users. When users receive a TGT, they can authenticate to
network services within the Kerberos realm represented by the KDC.
Authenticating to a Boundary Switch, page 7-42
Obtaining a TGT from a KDC, page 7-43
Authenticating to Network Services, page 7-43
The user opens an un-Kerberized Telnet connection to the boundary switch.
The switch prompts the user for a username and password.
The switch requests a TGT from the KDC for this user.
The KDC sends an encrypted TGT that includes the user identity to the switch.
Chapter 7
The Kerberos principal name must be in all lowercase characters.
Configuring Switch-Based Authentication
OL-12247-04