Exam 300-620 topic 1 question 224 discussion

In Cisco ACI, while the External Management Instance Profile specifies the IP addresses or subnets of external management services (like NTP, DNS, or syslog servers), it only defines the reachability of these services. The actual permissions for communication—meaning which type of traffic (like NTP) is allowed—are controlled through contracts applied to the management EPG (in this case, the Out-of-Band EPG if using OOB management).

voting C. IP is reachable because icmp is fine

Vote C, answer A doesn't make much sense.

It is C The sentence : both servers are reachable via the out-of-band management network, mean the are contract with ICMP, but doesn't have NTP

vote A

C - Fabric -> Fabric Policies -> Policies -> Pod -> Date and Time olicy folder structure named default ssign the IP/hostname of our NTP server and select the Management EPG our NTP server is accessible from [Management EPG] Fabric -> Fabric Policies -> Pods -> Policy Groups -> [Pod Policy Group - default] - Date Time Policy (selector) https://howtoaci.com/2019/05/30/ntp-configuration-in-aci/

See my explanations

Prior to configuring NTP, consider what management IP address scheme is in place within the ACI fabric. There are two options for configuring management of all ACI nodes and Application Policy Infrastructure Controllers (APICs), in-band management and/or out-of-band management. Another consideration in deploying time synchronization is where the time source is located. The reliability of the source must be carefully considered when determining if you will use a private internal clock or an external public clock. Out-of-band management NTP - When an ACI fabric is deployed with out-of-band management, each node of the fabric, inclusive of spines, leaves, and all members of the APIC cluster, is managed from outside the ACI fabric. This IP reachability will be leveraged so that each node can individually query the same NTP server as a consistent clock source. To configure NTP, a Date and Time policy must be created that references an out-of-band management endpoint group. Date and Time policies are confined to a single pod and must be deployed across all pods provisioned in the ACI fabric. Currently only one pod per ACI fabric is allowed.

I think A, because it already says that OOB network can reach the NTP servers IPs, ruling out the contract issue in my opinion