krb5kdc is the Kerberos version 5 Authentication Service and Key Distribution
Center (AS/KDC).
The
-r realm option specifies the realm for which the server should provide service;
by default the realm returned by
krb5_default_local_realm(3) is used.
The
-d dbname option specifies the name under which the principal database can be found; by
default the database is in DEFAULT_DBM_FILE.
The
-k keytype option specifies the key type of the master key in the database; the default
is KEYTYPE_DES.
The
-M mkeyname option specifies the principal name for the master key in the database;
the default is KRB5_KDB_M_NAME (usually "K/M" in the KDC's realm).
The
-p portnum option specifies the default UDP port number which the KDC should listen on for
Kerberos version 5 requests. This value is used when no port is specified in
the KDC profile and when no port is specified in the Kerberos configuration
file.
If no value is available, then the value in /etc/services for service
"kerberos" is used.
The
-m option specifies that the master database password should be fetched
from the keyboard rather than from a file on disk.
The
-4 option specifies how the KDC responds to kerberos IV requests for
tickets. The command line option overrides the value in the KDC
profile. The possible values are
none, disable, full or
nopreauth. These instruct the KDC to not respond to V4 packets, to
respond with a version skew error, to issue tickets for all database
entries, and to issue tickets for all but preauthentication required
database entries respectively. The default behaviour is as if
none was specified.
The
-n option specifies that the KDC does not put itself in the background
and does not disassociate itself from the terminal. In normal
operation, you should always allow the KDC to place itself in
the background.
The KDC may service requests for multiple realms (maximum 32 realms). The
realms are listed on the command line. Per-realm options that can be
specified on the command line pertain for each realm that follows it and are
superceded by subsequent definitions of the same option. For example,
specifies that the KDC listen on port 2001 for REALM1 and on port 2002 for
REALM2 and REALM3. Additionally, per-realm parameters may be specified in the
kdc.conf file. The location of this file may be specified by the
KRB5_KDC_PROFILE environment variable. Parameters specified in this file take precedence over
options specified on the command line. See the
kdc.conf(5) description for further details.