Brocade Communications Systems 6650 - page 42

24 Brocade ICX 6650 Administration Guide
53-1002600-01
Configuring the device as an SNTP server
2
To use the device as a an SNTP server, enter a command such as the following at the Privileged
EXEC level.
Brocade(config)# sntp server-mode use-local-clock authentication-key abc123
Brocade(config)# write memory
The above example configures the device to operate as an SNTP server with the local clock as a
reference backup and an authentication key of “abc123” and writes the configuration changes to
memory.
Syntax: [no] sntp server-mode [ use-local-clock [ stratum <stratum-number> ] ] [
authentication-key <key-string> ]
•The use-local-clock option causes the Brocade device to use the local clock as a reference
source if an upstream reference source becomes unavailable. The SNTP stratum number is set
to 1 by default. You may specify a different stratum number using the stratum option;
<stratum-number> must be between 1 and 15. When the internal clo ck is servi ng as the SNTP
reference source, the Brocade device will use the specified stratum number (or the default
value of 1). When it is synchronized with the upstream server, the Brocade device will use the
upstream server’s stratum number plus 1.
If you do not include the use-local-clock option the Brocade device will function as specified by
RFC 4330: when the Brocade device loses upstream synchronization, it will respond to client
SNTP requests with a “kiss-of-death” response (stratum value=0).
NOTE
To enable the use-local-clock option, you must set the internal clock of the Brocade device
either by SNTP synchronization (see “Specifying an SNTP server” on page 20) or by using the
clock set command (see “Setting the system clock” on page26). Until the internal clock is set,
the Brocade device will continue to rely exclusively on an upstream SNTP server if one is
reachable. If none, the SNTP server of the Brocade device is disabled (down).
•To require a code string for authentication of SNTP communication from clients, use the
authentication-key option and enter a key string of up to 16 characters. When this option is
used, authentication parameters are required in clients’ SNTP request messages. If
authentication fails, the Brocade device will reply with stratum 0 and a reference ID code of
“CRYP” (cryptographic authentication or identification failed), and messages received without
the required parameters will be dropped.
NOTE
Once entered, the authentication key cannot be viewed. Using the show running-config
command will show output similar to the following when an authentication key has been set:
sntp server-mode authentication-key 2 $QHMiR3NzQA=
The 2 indicates that the key is encrypted using base-64 encryption; the characters following
the 2 are the encrypted authentication string.
NOTE
You cannot enable or disable the use-local-clock option (or its stratum number) or change the
authentication string when the SNTP server is up. To change these settings after enabling SNTP
server mode, you must disable server mode using the command no sntp server-mode, then
re-enable it with the new parameters.