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FQDN Management and Allocation

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FQDN Management and Allocation

Introduction

3CX Provided Domain

Customer Owned Domain

Free Licence Key Usage

DNS TTL

Altering the FQDN

Summary

See also

Introduction

When 3CX V15 is first installed, the license key chosen by the administrator will be bound to the FQDN. It is therefore essential that the administrator carefully chooses the desired FQDN during the initial setup. In order to follow the steps below this must be the first time you are setting up your FQDN and must be on V15 SP4 or later.

3CX Provided Domain

Starting with V15, customers with valid maintenance can receive an external DNS entry within certain 3CX top level domains - free of charge. In addition to managed FQDNs, users will also be supplied with a state of the art, widely trusted SSL certificate issued by Let’s Encrypt.

Please note: once you have decided on the userpart of the FQDN (userpart.hostpart.tld) and a domain suffix (userpart.hostpart.tld), this combination is bound to the license key. Every FQDN will also create a WebMeeting URL based on the following syntax:

  1. userpart.hostpart.tld -> userpart-tld.3cx.net
  • Regular domains:
    customer.3cx
    .de -> customer-de.3cx.net
    Customer.3cx
    .us -> customer-us.3cx.net
  • Dual level domains
    customer.3cx
    .co.uk -> customer-uk.3cx.net
    customer.3cx
    .co.nz -> customer-nz.3cx.net
    customer.3cx
    .com.tr -> customer-tr.3cx.net
    customer.3cx
    .co.za -> customer-za.3cx.net
  • Exceptions domains
    customer.
    elastix.com -> customer-ecom.elastix.net
    City Domains are shortened to the first 3 letters
    customer.3cx.
    barcelona -> customer-bar.3cx.net
  • Dual Level Sub Domains
    customer.
    north.3cx.us -> cusomer-north-us.3cx.net

Note: 3CX reserves the right to revoke, without any warning, any FQDN which might:

  • Breach another company’s trademark rights
  • Be used for purposes other than hosting 3CX
  • Be of an offensive or racist nature
  • Required by 3CX (will be handled with the partner for the transition to a new fqdn)

Users also have no right to claim an FQDN which is already in use.

All available domains are distributed on availability and may closed if exhausted for the time being. Therefore it cannot be guaranteed that domain suffixe are available even if the domain was previously bound to a license key.

Customer Owned Domain

If the installation is installed on a customer owned domain (requires Pro or Enterprise Edition), a valid public trusted certificate covering the 3CX installation must also be present during installation. A Let’s Encrypt Cert cannot be issued by 3CX in this case.

Additionally, the license key will be bound to the customer FQDN. Every FQDN will also create a 3CX WebMeeting URL based on the following syntax:

  1. userpart.hostpart.tld -> userpart-hostpart-tld.3cx.net
  • Samples
    customer.domain.com -> customer-domain-com.3cx.net
    customer.domain.co.uk -> customer-domain-co-uk.3cx.net
    pbx.customer.domain-part.co.nz -> pbx-customer-domain-part-co-nz.3cx.net

Free Licence Key Usage

Free licence keys (commercial and NFR keys are exempt from this rule) which have not been used for 3 months will be unbound from their reserved FQDN and can be reserved by others. The “in use” state is evaluated upon key activation.

DNS TTL

When you use a 3CX FQDN, the DNS TTL (time to live) depends on the 3CX License used. Standard and Professional licenses have a TTL of 6 hours. Enterprise Editions however, set the TTL to 300 seconds. This allows for immediate failover which will update the 3CX FQDN to the IP of the new server in less than 5 minutes. The shorter the TTL, the quicker the FQDN Mapping to IP updates.

Altering the FQDN

Read here if you would like to change an already bound FQDN: https://www.3cx.com/docs/key-already-bound/

Summary

  1. First time installation binds the FQDN to the key
  2. In case the chosen FQDN is already in use:
  • Error creating FQDN: FQDN already in use. Please choose another one
  • Solution: Pick another free FQDN
  1. Subcentral installation of the same key required to enter the same FQDN
  2. In case the entered FQDN does not match:
  • Error creating FQDN: License key already bound to another FQDN.
  • Solution A: Login to the customer.3cx.com and check what the binded FQDN is
  • Solution B: Login to the customer.3cx.com and release the FQDN to choose a new one
  1. In case the entered domain suffix is exhausted:
  • Domain zone XYZ is exhausted and can not be used. Please choose another domain.
  • Solution: Pick another domain suffix

See also