Thank you for you reply, but your solution doesn't work. I have set up DNS server in VLAN 1, but nothing changed.     I found issue by myself in Security & SD-WAN -> Threat protection. I disabled Umbrella protection and now DNS traffic flows between VLANs normally. Additionally, if two domain controllers are located in different VLANs and Umbrella protection enabled, DNS replica stops and both domain controllers are not able to exchange records update.   Topic can be closed. ... View more