Bind Formula

The Bind formula is used to configure the Domain Name System (DNS) on the branch server. POS terminals will use the DNS on the branch server for name resolution of Saltboot specific hostnames.

When you are configuring the Bind formula for a branch server with a dedicated internal network, check that you are using the same fully qualified domain name (FQDN) on both the external and internal branch networks. If the FQDN does not match on both networks, the branch server will not be recognized as a proxy server.

The following procedure outlines a standard configuration with two zones. Adjust it to suit your own environment.

Zone 1 is a regular domain zone. Its main purpose is to resolve Saltboot hostnames such as TFTP, FTP, or Salt. It can also resolve the terminal names if configured.

Zone 2 is the reverse zone of Zone 1. Its main purpose is to resolve IP addresses back to hostnames. Zone 2 is primarily needed for the correct determination of the FQDNs of the branch.

Procedure: Configuring Bind with Two Zones

  1. Check the Bind formula, click Save, and navigate to the Formulas  Bind tab.

  2. In the Config section, select Include Forwarders.

  3. In the Configured Zones section, use these parameters for Zone 1:

    • In the Name field, enter the domain name of your branch network (for example: branch1.example.com).

    • In the Type field, select master.

  4. Click Add item to add a second zone, and set these parameters for Zone 2:

    • In the Name field, use the reverse zone for the configured IP range (for example: com.example.branch1).

    • In the Type field, select master

  5. In the Available Zones section, use these parameters for Zone 1:

    • In the Name field, enter the domain name of your branch network (for example: branch1.example.org).

    • In the File field, type the name of your configuration file.

  6. In the Start of Authority (SOA) section, use these parameters for Zone 1:

    • In the Nameserver (NS) field, use the FQDN of the branch server (for example: branchserver.branch1.example.org).

    • In the Contact field, use the email address for the domain administrator.

    • Keep all other fields as their default values.

  7. In the Records section, in subsection A, use these parameters to set up an A record for Zone 1:

    • In the Hostname field, use the hostname of the branch server (for example: branchserver).

    • In the IP field, use the IP address of the branch server (for example, 192.168.1.5).

  8. In the Records section, subsection NS, use these parameters to set up an NS record for Zone 1:

    • In the input box, use the hostname of the branch server (for example: branchserver).

  9. In the Records section, subsection CNAME, use these parameters to set up CNAME records for Zone 1:

    • In the Key field, enter tftp, and in the Value field, type the hostname of the branch server (for example: branchserver).

    • Click Add Item. In the Key field, enter ftp, and in the Value field, type the hostname of the branch server.

    • Click Add Item. In the Key field, enter dns, and in the Value field, type the hostname of the branch server.

    • Click Add Item. In the Key field, enter dhcp, and in the Value field, type the hostname of the branch server.

    • Click Add Item. In the Key field, enter salt, and in the Value field, type the FQDN of the branch server (for example: branchserver.branch1.example.org).

  10. Set up Zone 2 using the same parameters as for Zone 1, but ensure you use the reverse details:

    • The same SOA section as Zone 1.

    • Empty A and CNAME records.

    • Additionally, configure in Zone 2:

      • Generate Reverse field by the network IP address set in branch server network formula (for example, 192.168.1.5/24).

      • For Zones should specify the domain name of your branch network (for example, branch1.example.org).

  11. Click Save Formula to save your configuration.

  12. Apply the highstate.

Reverse name resolution on terminals might not work for networks that are inside one of these IPv4 private address ranges:

  • 10.0.0.0/8

  • 172.16.0.0/12

  • 192.168.0.0/16

If you encounter this problem, go to the Options section of the Bind formula, and click Add item:

  • In the Options field, enter empty-zones-enable.

  • In the Value field, select No.