Hi there. I have issue with MX84 (firmware MX 15.42.1) and local DNS server. My network configuration has 3 VLANs
I don't use DHCP in my VLAN 3 (static IP assignment)
My DNS server (Windows Server 2012R2 with Active Directory) is located in VLAN1. When I try to resolve from VLAN 3 any DNS record that my DNS server holds, I see reply from public DNS.
I can ping server in different VLAN or reach it with tracert, but only by IP, so it's not a routing issue. Here is my interface configuration
In same VLAN where my DNS server is located, there is no issue with DNS resolving.
What settings must I change for using my local DNS server in all VLANs?
You need to configure the DHCP settings for VLAN 1 with your internal DNS server (i.e. the Windows Server 2012R2). In the DHCP configuration change the 'DNS nameservers' to 'Specify nameservers...' and then enter the IP address of your Windows DNS server in the 'Custom nameservers' box.
Once the configuration has been pushed to the MX you'll need to refresh the DHCP lease on the client. At this point the client should receive the DNS settings for your Windows server, so when you do an 'ipconfig /all' the 'DNS Servers' line should show the IP address of your Windows server.
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.
