Pre

• Synology DSM 7.0.1-42218
• DNS Server from the “Package Center” needs to be installed.
• Reverse Proxy can be found under “Control Panel -> Login Portal -> Advanced”

Domain

• We need a Domain
  • home.arpa is the Domain we are using for Home purposes - https://datatracker.ietf.org/doc/html/rfc8375

DNS

• DNS Server
  • Zones -> Create -> Master zone
    • Domain type: Forward zone
    • Domain name: home.arpa
    • Master DNS server: Synology IP Address
    • Serial format: Integer
    • Limit zone transer: check
    • Limit source IP service: uncheck
    • Enable slave zone notification: uncheck
    • Limit zone update: check
  • Resolution
    • Enable resolution service: check
    • Limit source IP service: uncheck
    • Enable forwarders
      • Forwarder 1: 1.1.1.1
      • Forwarder 2: 8.8.8.8
      • Forward policy: Forward first

Now we can configure the “resource records”.

Let us assume Plex is running as a Docker Container on the Nas.

The IP of the Nas is 192.168.0.10. Plex uses 192.168.0.10:32400.

First we create two more “Resource Records”.

• CNAME type
  • Name: *
  • TTL: 86400
  • Canonical name: home.arpa
• A type
  • Name:
  • TTL: 86400
  • IP address: 192.168.0.10

With this setup every Subdomain of home.arpa points to 192.168.0.10, e.g. a.home.arpa, b.home.arpa and plex.home.arpa.

Reverse Proxy

Now we need to configure the reverse Proxy.

• Control Panel -> Login Portal -> Advanced -> Reverse Proxy
• Create
  • Source
    • Reverse Proxy Name: plex
    • Protocol: HTTP
    • Hostname: plex.home.arpa
    • Port: 80
  • Destination
    • Protocol: HTTP
    • Hostname: 192.168.0.10
    • Port 32400

We need to manually specify the DNS Server on our Computer. Set it to our Nas IP, e.g. 192.168.0.10.

Now we should be able to use plex.home.arpa instead of 192.168.0.10:32400/web/index.html#!/.