Public IP, publish DNS

Jyge Posts: 2
First Comment
edited April 2021 in Security
Need to set up Zywall 110 with public IP-addresses, which we have.
-have two public DNS-server which must be publish to internet
-public IP:s have used also on LAN (dhcp)

What is the best way to configure fw and publish DNS servers? 

Firmware 4.32

Public address range:
xxx.65.126.1 - xxx.65.126.256
xxx.65.1267.1 - xxx.65.127.256

xxx.65.126.1 (router)
xxx.65.126.2 (fw)
xxx.65.126.7 (switch)

xxx.65.127.5 (NS1) - public DNS server
xxx.65.127.10 (NS2)  - public DNS server

xxx.65.126.10 - xxx.65.126.90 (dhcp)

All Replies

  • Alfonso
    Alfonso Posts: 257  Master Member
    First Anniversary Friend Collector First Answer First Comment
    Hi @Jyge

    Only some recommendations:

    - Your public DNS default gateway must be the Firewall's ip
    - Your firewall Default gateway must be the router's ip
    - remove the public ip address os the switch unless it is completely necessary.
    - Add a policy rule:
     Source: ANY
     Destination: Public DNS
     Service: DNS
     Action: Allow
    - Add another policy rule if your DNS are caching:
     Source: Public DNS
     Destination: ANY
     Service: DNS
     Action: Allow

    I   hope it helps you,


  • Zyxel_Stanley
    Zyxel_Stanley Posts: 1,366  Zyxel Employee
    First Anniversary 10 Comments Friend Collector First Answer

    Hi @Jyge

    You can add a bridge interface for this requirement. 

    Go to Configuration > Network > Interface > Bridge Click Add button.

    (1) Setup interface, zone and member of interfaces.

    (2) Set IP address for this interface

    (3) Setup DHCP function for DHCP client.

    (4) Add policy control rule for incoming DSN query.

    Due to DNS server with public IP address, so port forwarding rule is unnecessary.

  • Jyge
    Jyge Posts: 2
    First Comment
    Thanks Zyxel_Stanley!

    Get it done. Was some issues with DCHP, but no it work.

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