Technical Tip: DNS Service in Recursive Mode with Shadow DNS Database

Description

This article describes about DNS service proxy mode Recursive on FortiExtender.

When DNS service is on Recursive mode, FortiExtender interface firstly query local shadow DNS database; If no naming resolution in local shadow DNS database, the DNS query will be forwarded to DNS servers, which are defined and acquired on System DNS pool.

Scope

FortiExtender DNS proxy service in Recursive mode.

Solution

1) On FortiExtender go to Networking - > DNS Servers.

2) Create DNS Service with Recursive mode.

3) On CLI, check DNS proxy service.

4) On CLI, check DNS server in DNS server pool.

5) On client, send DNS request. If the request has naming resolution in shadow DNS database.

6) On FortiExtender, DNS log message displays the processing on recursive mode.

7) On client, send DNS request. If the request has NO naming resolution in shadow DNS database, DNS query will be forwarded to system DNS servers.

8) On FortiExtender, Debug log message shows the sequence of DNS processing in recursive mode.