Configuring NTP
The device does not have a hardware-supported clock and cannot function as an NTP primary clock to which
peers synchronize themselves when an external NTP source is not available. The device also has no hardware
support for a calendar. As a result, the
ntp update-calendar
and the
ntp master
commands in global
configuration mode are not available.
These following sections provide configuration information on NTP:
Default NTP Configuration
shows the default NTP configuration.
Table 3: Default NTP Configuration
Default Setting
Feature
Disabled. No authentication key is specified.
NTP authentication
None configured.
NTP peer or server associations
Disabled; no interface sends or receives NTP
broadcast packets.
NTP broadcast service
No access control is specified.
NTP access restrictions
The source address is set by the outgoing interface.
NTP packet source IP address
NTP is enabled on all interfaces by default. All interfaces receive NTP packets.
Configuring NTP Authentication
To configure NTP authentication, perform this procedure:
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
[
no
]
ntp authenticate
4.
[
no
]
ntp authentication-key number
{
md5
|
cmac-aes-128
|
hmac-sha1
|
hmac-sha2-256
}
value
5.
[
no
]
ntp authentication-key number
{
md5
|
cmac-aes-128
|
hmac-sha1
|
hmac-sha2-256
}
value
6.
[
no
]
ntp authentication-key number
{
md5
|
cmac-aes-128
|
hmac-sha1
|
hmac-sha2-256
}
value
7.
[
no
]
ntp trusted-key key-number
8.
[
no
]
ntp server ip-address key key-id
[
prefer
]
9.
end
DETAILED STEPS
Purpose
Command or Action
Enables privileged EXEC mode.
enable
Step 1
Example:
Enter your password if prompted.
System Management Configuration Guide, Cisco IOS XE Gibraltar 16.10.x (Catalyst 9200 Switches)
16
Administering the Device
Configuring NTP
