# Architecture DNS ```mermaid flowchart LR subgraph External recursor GandiDns[ Gandi ducamps.win] end subgraph Internal pihole[pihole]--ducamps.win-->NAS pihole--service.consul-->consul[consul cluster] NAS--service.consul-->consul end NAS --> recursor pihole --> recursor ``` ## Detail Pihole container in nomad cluster is set as primary DNS as add blocker secondary DNS is locate on NAS DNS locate on NAS manage domain *ducamps.win* on local network pihole forward each request on *ducamps.win* to this DNS. Each DNS forward *service.consul* request to the consul cluster. On Pihole a template configure each consul server. On diskstation every request as forward to one consul node this point is to improve we because we have a possibility of outtage. du to synology DNSServer limitation we only put a forward on port 53 so we need on the target consul node to redirect port 53 to 8300 by iptables rules. external recursor are on cloudflare and FDN