In a VMware NSX for vSphere 6.x environment where Spoofguard is enabled or disabled and ARP Snooping as IP Detection Type is configured, you see this symptom:
In the NSX Manager vsm.log file, you see a warning similar to:
WARN: Spoofguard configuration update number 1485967964780 to host host-### timed out. Spoofguard configuration on host is synced up to version 0.
This issue is resolved in VMware NSX for vSphere 6.3.2.