Cisco WS-C2980G-A Software Guide - Page 478

Mapping a Kerberos Realm to a Host Name or DNS Domain, Copying SRVTAB Files

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Configuring Authentication Chapter 30 Configuring Switch Access Using AAA Mapping a Kerberos Realm to a Host Name or DNS Domain Optionally, you can map a host name or Domain Name Server (DNS) domain to a Kerberos realm. To map a Kerberos realm to either a host name or DNS domain, perform this task in privileged mode: Step 1 Step 2 Task Command (Optional) Map a host name or DNS domain to a Kerberos realm. set kerberos realm {dns-domain | host} kerberos-realm Clear the Kerberos realm domain or host mapping entry. clear kerberos realm {dns-domain | host} kerberos-realm This example shows how to map a Kerberos realm, called CISCO.COM, to a DNS domain and how to clear the entry: Console> (enable) set kerberos realm CISCO CISCO.COM Kerberos DnsDomain-Realm entry set to CISCO - CISCO.COM Console> (enable) Console> (enable) clear kerberos realm CISCO CISCO.COM Kerberos DnsDomain-Realm entry CISCO - CISCO.COM deleted Console> (enable) Copying SRVTAB Files To allow remote users to authenticate to the switch using Kerberos credentials, the switch must share a key with the KDC. You must give the switch a copy of the file that is stored in the KDC that contains the key. These files are called SRVTAB files on the switch and KEYTAB files on the servers. The most secure method of copying SRVTAB files to the hosts in your Kerberos realm is to copy them onto physical media and then manually copy the files onto the system. To copy SRVTAB files to a switch that does not have a physical media drive, you must transfer them through the network by using the Trivial File Transfer Protocol (TFTP). When you copy the SRVTAB file from the switch to the KDC, the switch parses the information in this file and stores it in the running configuration in the Kerberos SRVTAB entry format. If you enter the SRVTAB directly into the switch, create an entry for each Kerberos principal (service) on the switch. The entries are maintained in the SRVTAB table. The maximum size of the table is 20 entries. To retrieve SRVTAB files to the switch from the KDC, perform this task in privileged mode: Step 1 Step 2 Task Command Retrieve a specified SRVTAB file from the KDC. set kerberos srvtab remote {hostname | ip-address} filename (Optional) You can enter the SRVTAB directly into the switch. set kerberos srvtab entry kerberos-principal principal-type timestamp key-version number key-type key-length encrypted-keytab 30-34 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 78-15486-01

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30-34
Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide
Release 8.1
78-15486-01
Chapter 30
Configuring Switch Access Using AAA
Configuring Authentication
Mapping a Kerberos Realm to a Host Name or DNS Domain
Optionally, you can map a host name or Domain Name Server (DNS) domain to a Kerberos realm.
To map a Kerberos realm to either a host name or DNS domain, perform this task in privileged mode:
This example shows how to map a Kerberos realm, called CISCO.COM, to a DNS domain and how to
clear the entry:
Console> (enable)
set kerberos realm CISCO CISCO.COM
Kerberos DnsDomain-Realm entry set to CISCO - CISCO.COM
Console> (enable)
Console> (enable)
clear kerberos realm CISCO CISCO.COM
Kerberos DnsDomain-Realm entry CISCO - CISCO.COM deleted
Console> (enable)
Copying SRVTAB Files
To allow remote users to authenticate to the switch using Kerberos credentials, the switch must share a
key with the KDC. You must give the switch a copy of the file that is stored in the KDC that contains the
key. These files are called SRVTAB files on the switch and KEYTAB files on the servers.
The most secure method of copying SRVTAB files to the hosts in your Kerberos realm is to copy them
onto physical media and then manually copy the files onto the system. To copy SRVTAB files to a switch
that does not have a physical media drive, you must transfer them through the network by using the
Trivial File Transfer Protocol (TFTP).
When you copy the SRVTAB file from the switch to the KDC, the switch parses the information in this
file and stores it in the running configuration in the Kerberos SRVTAB entry format. If you enter the
SRVTAB directly into the switch, create an entry for each Kerberos principal (service) on the switch.
The entries are maintained in the SRVTAB table. The maximum size of the table is 20 entries.
To retrieve SRVTAB files to the switch from the KDC, perform this task in privileged mode:
Task
Command
Step 1
(Optional) Map a host name or DNS domain to a
Kerberos realm.
set kerberos realm
{
dns-domain | host
}
kerberos-realm
Step 2
Clear the Kerberos realm domain or host mapping entry.
clear kerberos realm
{
dns-domain | host
}
kerberos-realm
Task
Command
Step 1
Retrieve a specified SRVTAB file from the KDC.
set kerberos srvtab remote
{
hostname
|
ip-address
}
filename
Step 2
(Optional) You can enter the SRVTAB directly
into the switch.
set kerberos srvtab entry
kerberos-principal
principal-type
timestamp
key-version number
key-type
key-length
encrypted-keytab