FortiGate
FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
aabukhshim
Staff
Staff
Article Id 331347

Description

 

This article describes the steps to configure DHCP option 119 on FortiGate.

 

Scope

 

FortiOS.

 

Solution

 

Configuration Example Requirements:

  • FortiGate’s DHCP server must be configured to use DHCP option 119 for the below domains:
    • test1.local
    • test2.net
    • test3.org

Preparing for the configuration:

  •  Break each domain and convert it to Hex, and find the length of each string.
    • test1.local
      • test1 = 7465737431
      • local = 6c6f63616c   
    • test2.net
      • test2 = 7465737432
      • net = 6e6574
    • test3.net
      • test3 = 7465737433
      • org = 6f7267
    • Find the length of each string:
      • test1.local
        • test1 = 05
        • local = 05   
      • test2.net
        • test2 = 05
        • net = 03
      • test3.net
        • test3 = 05
        • org = 03
      • Prepare and append each domain in Hex (string length then string in HEX)
        • test1.local
          •  057465737431056c6f63616c   
        • test2.net
          • 057465737432036e6574
        • test3.net
          • 057465737433036f7267
        • Prepare the HEX for all domains and add 00 in between and 00 at the end
          • test1.local00test2.net00test3.net00
            • 057465737431056c6f63616c00057465737432036e657400057465737433036f726700

FortiGate’s Configuration:

  • CLI Configuration:

config system dhcp server

edit 1

config options

edit 1

set code 119

set value "057465737431056c6f63616c00057465737432036e657400057465737433036f726700"

next

end

next

end

  • GUI Configuration

Network -> Interface -> select an interface -> DHCP server -> Advanced -> Additional DHCP option -> Create New.

 

1.png

 

Verification:

 

2.png

 

3.png

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