NTP uses the User Datagram Protocol (UDP) & all NTP communications use Coordinated Universal Time (UTC).
NTP uses a Stratum to describe the distance between a network device and an authoritative time source. A stratum 1 time server is directly attached to an authoritative time source (such as a radio or atomic clock or a GPS time source). A Stratum 2 NTP server receives its time through NTP from a stratum 1 time server.
Configure Out-of-Band Management
Step 1: Go to the Tenants menu, select the mgmt tenant, navigate to Node Management Addresses > Static Node Management Addresses and right-click the menu to Create Static Node Management Addresses.
Step 2 : Configure the OOB management addresses for nodes 101–102 (leaf-a and leaf-b) with the settings below. Then click Submit and Yes to confirm the configuration.
Node Range: 101-102
Config: Select Out-Of-Band Addresses
Out-Of-Band management EPG: default
Out-Of-Band IPv4 address (include the mask): 192.168.10.211/24
Out-Of-Band IPv4 gateway: 192.168.10.254
Note: The defined IP address is assigned to node 101, the next incremented IP address is assigned to node 102.
Similarly Configure the OOB management address for node 201 (spine) with the settings below. Then click Submit and Yes to confirm the configuration.
Node Range: 201-201
Config: Select Out-Of-Band Addresses
Out-Of-Band management EPG: default
Out-Of-Band IPv4 address (include the mask): 192.168.10.213/24
Out-Of-Band IPv4 gateway: 192.168.10.254
Step 3: Verify if management ip address is properly configured
GUI
Fabric > Inventory > Pod 1, select a switch and choose the General tab.
You can also examine the OOB management IP address from Inventory by expanding the switch and selecting Interfaces > Management Interfaces > mgmt0
leaf-a# show vrf
VRF-Name VRF-ID State Reason
black-hole 3 Up --
management 2 Up --
overlay-1 4 Up --
leaf-a# show ip interface brief vrf management
IP Interface Status for VRF "management"(2)
Interface Address Interface Status
mgmt0 192.168.10.211/24 protocol-up/link-up/admin-up
Let's Configure NTP
The NTP configuration will be applied to the fabric.
Step1: Date and Time Policy
Fabric > Fabric Policies > Policies > Pod > Date and Time. Right-click the menu and select Create Date and Time Policy.
Step2: Name the policy NTP, leave the states unchanged (administrative state enabled, server state disabled, authentication state disabled) and click Next.
Click the plus sign (+) in the table to add an NTP server with the settings below. Leave other settings at their default values, then click OK and Finish.
Name: 192.168.10.15 (IP address of your StudentPC, which is running an NTP daemon)
Management EPG: default (Out-of-Band).
Step3: In Fabric > Fabric Policies > Pods, right-click Policy Groups to Create Pod Policy Group.
Step 4: Configure the pod policy group name Pod_PG and choose the Date Time policy NTP. Click Submit.
Step 5: Fabric > Fabric Policies > Pods > Profiles > Pod Profile default > default. Choose the pod selector default and select the Pod_PG policy from the Fabric Policy Group drop-down. Click Update and Continue.
Step 6: Fabric > Fabric Policies > Policies > Pod > Date and Time > Policy NTP > NTP Server 192.168.10.15, select the Operational tab and examine the Sync Status.
apic1# ntpstat
synchronised to NTP server (192.168.10.15) at stratum 14
time correct to within 16 ms
polling server every 16 s
Note: If the NTP server was the preferred one and was deleted. This could result in a ntp sync issue.
Please add back it as preferred server
The devices will sync to it … remove it as preferred ntp server and remove it again.
Copy the current ntp configuration to ntp.conf.dhcp
cp /etc/ntp.conf /var/lib/ntp/ntp.conf.dhcp
Restart NTP service (systemctl restart ntp)
Disable and enable ntp feature on leaf switch.
Logs for NTP
/var/sysmgr/tmp_logs/ntpwd.log
/var/sysmgr/mem_logs/ntpd_logs
leaf# show ntp (ESC) (ESC) authentication-keys internal peers statistics authentication-status peer-status server-info trusted-keys
leaf# show ntp peer-status Total peers : 0 * - selected for sync, + - peer mode(active), - - peer mode(passive), = - polled in client mode remote local st poll reach delay vrf
If there is no connection to the NTP server, whether through out-of-band or in-band, the switch will not be able to provide NTP peer status information.