Worldwide users from an organization are experiencing intermittent access to a global cloud application. The cloud provider availability dashboard shows all resource availability has been 100% in…

Checking firewall rules on the headquarters site might be relevant if only headquarters users were affected, but "worldwide users" indicates a more global or fundamental issue beyond a single site's firewall.

Restarting the application and applicable services might resolve transient issues, but the problem is with intermittent access by worldwide users to a cloud application, and the provider reports 100% availability, making it less likely to be a simple application crash on the provider's side.

Allowing all traffic from any private IP address at the cloud provider side is a severe security risk and is unlikely to be the cause of intermittent access, as private IP addresses are typically used within internal networks, not for external global user access to a public cloud application.

Intermittent access to a global application, especially when the provider reports no issues, strongly suggests a DNS problem. Incorrect or outdated DNS records can cause users to be directed to non-existent or incorrect application endpoints, leading to intermittent connectivity issues depending on local DNS caching or which DNS server is being used. DNS issues are common and can affect users globally without indicating a cloud provider or network infrastructure failure.