Reverse DNS lookups

Our reverse DNS lookup zone in AD is no longer getting updates from DHCP clients on our Peplinks. Only statically assigned hosts are showing up with reverse lookup records. NSLookup <IPADDRESS> is failing with (unknown domain error). We recently had a domain controller fail and it appears that the updates stopped around that time. Is there anything with Peplink that would prevent AD updates to DNS for DHCP clients?


Can you provide network diagram to show where is the AD server, DHCP clients and related network devices? This allow me to understand better which part may contribute the problem.