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iskandar_lie
Staff
Staff
October 2, 2022

Technical Tip: Implement split DNS for Local and Global domain

  • October 2, 2022
  • 0 replies
  • 12415 views
Description This article describes how to implement split DNS for Local and Global domain.
Scope FortiGate DNS feature version 7.2.1.
Solution

Scenario:

1) The local DNS server will be used to resolve only the local name server,

2) Global DNS server, in this case, FortiGuard DNS server, will be used to resolve global DNS query.

 

Diagram:

 

iskandar_lie_0-1664710495217.png

 

Local domain name : 40gate.co.id

Secondary DNS server: 172.16.10.254 (IP address of local DNS server).

 

iskandar_lie_1-1664710532463.png

 

Note.

Secondary DNS server showing 'unreachable' is EXPECTED here.

Just to only resolve  the local DNS name.

 

Fortigate DNS config: no firewall policy rule is required.

 

iskandar_lie_2-1664710587361.png

 

User config:

set the user to request DNS to the FortiGate DNS interface: 192.168.16.1.

 

iskandar_lie_3-1664710613841.png

 

Local DNS can successfully be resolved:

 

iskandar_lie_4-1664710641276.png

 

Global DNS can successfully be resolved:

 

iskandar_lie_5-1664710665983.png

 

DNS request process on FortiGate.

 

iskandar_lie_6-1664710687290.png

 

DNS cache.

 

iskandar_lie_7-1664710709961.png

 

Related documents:

https://docs.fortinet.com/document/fortigate/6.2.0/cookbook/960561/fortigate-dns-server

https://docs.fortinet.com/document/fortigate/6.2.0/cookbook/121810/using-a-fortigate-as-a-dns-server

https://community.fortinet.com/t5/FortiGate/Technical-Tip-DNS-database-with-FortiGate-as-a-slave-to-a/ta-p/192942

https://community.fortinet.com/t5/FortiGate/Implement-Fortigate-as-a-Local-DNS-server-database/ta-p/225434

 

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