You must create a DNS delegation for the client's DNS request to be forwarded to the LoadMaster. This must be done for both private and public clients. To avoid confusion, this is explained from two perspectives:

  • The application user's point of view: From the application user's point of view, the FQDN is delegated to the GEO LoadMaster. A user delegates the FQDN mail.domain.com to the GEO LoadMaster.
  • The DNS administrator user's point of view: From the DNS administrator's point of view, the sub-domain is delegated to the GEO LoadMaster. A DNS administrator delegates the subdomain *mail.domain.com to the GEO LoadMaster. Any request matching this is forwarded to the GEO LoadMaster. For example:
    • Sales.mail.domain.com
    • QA.mail.domain.com
    • support.mail.domain.com
    • *.mail.domain.com
    • mail.domain.com

All of the FQDNs in the sub-domain mail.domain.com are delegated to the GEO LoadMaster including the FQDN mail.domain.com itself. In most cases, the only FQDN that matters is mail.domain.com. In this scenario, there are no other records in this sub-domain, for example, Sales.mail.domain.com and QA.mail.domain.com.

You can integrate the LoadMaster with your authoritative DNS with only a few DNS records:

  1. Create a new A record which is pointed to the LoadMaster, for example lm1.example.com. Create the corresponding PTR record for the reverse proxy lookup by IP. Forward-confirmed reverse DNS support is required.
  2. For each hostname that must be delegated to the LoadMaster, create an NS record and set the value to the A record created for the LoadMaster in the previous step, for example, www.web.example.com to lm1.example.com.

When using GEO LoadMaster active/active configuration, repeat step 1 for the second LoadMaster using a unique hostname, for example lm2.example.com. Repeat step 2 using the second LoadMaster. This results in two NS records for www.example.com; one pointing to lm1.example.com and one to lm2.example.com.

Here are some steps with screenshots:

Note: There may be a difference in the following steps depending on the DNS server selected (internal Microsoft DNS server, external, or third party DNS providers) but the purpose of creating the records remains the same.

  1. Open the DNS Manager. This shows existing records and records already created for GEO LoadMasters.

  2. Right-click the domain and select New Delegation.

  3. Click Next on the new delegation wizard.

  4. Set this to the FQDN/sub-domain that you want to delegate.

  5. In this example, the FQDN mail.kemptest.com (sub-domain *.mail.kemptest.com) is delegated.

  6. Select what to delegate this FQDN/sub-domain to the GEO LoadMaster.

  7. Add each GEO LoadMaster individually.

  8. Delegate this FQDN/sub-domain to these GEO LoadMasters.

  9. Click Finish.

Under the domain kemptest.com there is now a sub-domain that has a delegation and two NS records pointing to the two GEO LoadMasters.