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Rider
Rider
New Member
September 9, 2021
Question

Fortigate DNS Server reverse lookup

  • September 9, 2021
  • 3 replies
  • 12020 views

Hi,

 

my Foritgate is acting as a DNS server with static entrys. However a revrese lookup (ip to name) on a client which have fortigate as a DNS server configured gives no result.

 

Is there an additional setting which have to be configured for DNS reverse lookup?

 

Kind Regards,

 Juergen

    3 replies

    ede_pfau
    SuperUser
    ede_pfau
    SuperUser
    September 9, 2021

    In short (as I am on holidays and not at my desk):

    1- You need to create an additional zone, aptly named like a reverse zone.

    2- Populate it with PTR records instead of A records.

     

    Then the FGT will do reverse lookups. It is clumsy, and PTR records are not created automatically, but it works.

     

    jpveen
    jpveen
    New Member
    September 17, 2021

    did you configure PTR records for every A record you want the reverse lookup to work for? That's required to get reverse lookups working as far as I know.

    rik-e
    rik-e
    New Member
    April 13, 2022

    Hi Juergen,

     

    are you using an active directory by an chance?

    If so you could forward these requests to the domain dns servers.

     

    I did it this way and it works fine:

     

    conf system dns-database

    edit "10.in-addr.arpa"
    set domain "10.in-addr.arpa"
    set ttl 28800
    set authoritative disable
    set forwarder "[DC1]" "[DC2]"

     

    This way every PTR request for IPs of 10.0.0.0/8 gets forwarded.

     

     

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