When you configure vDiscovery jobs, you can enable the appliance to automatically create DNS records for discovered virtual entities in your VNets. When you enable this feature, NIOS automatically adds Host records or A and PTR records to the authoritative zones for the discovered IP addresses based on your configuration. You can also enter a formula that NIOS uses to create the DNS names for the discovered IP addresses based on their VM parameters such as vm_name or discovered_name for data discovered through Azure. By doing so, NIOS is able to discover public and private IP addresses by looking up the corresponding DNS names.
Discovered data includes IP addresses for the VMs and associated information such as VM name, VM ID, tenant ID, and others. Note that corresponding zones must already exist in order for NIOS to add DNS records. Otherwise, NIOS does not add any DNS records and it logs a message to the syslog.
NIOS automatically adds DNS records (in the network views specified for vDiscovery) based on the following conditions:
The corresponding DNS zones must already exist in the NIOS database. NIOS does not automatically create DNS zones for the records.
To create a PTR record, the corresponding reverse-mapping zone must exist.
A DNS zone cannot be associated with more than one DNS view. NIOS does not create DNS records for zones that are associated with multiple DNS views.
NIOS adds new DNS records only if the VM name for the discovered IP address is available and there is no conflict between the discovered data and the associated network view.
The following matrix captures some scenarios about how vDiscovery handles various actions and what the outcome is, for the information on the Cloud Platform appliance and in the NIOS database.
Note
vDiscovery modifies records that are created by the vDiscovery process only. It does not create or update DNS records that are originally created by other admin users.
Actions and Conditions | Cloud Platform Data before vDiscovery | Cloud Platform Data after vDiscovery | NIOS Data before vDiscovery | NIOS Data after vDiscovery |
|---|---|---|---|---|
| No data for vma | 10.10.10.1 | Zone: corpxyz.com | Zone: corpxyz.com |
| No data for vma | 10.10.10.1 | Zone: corpxyz.com | Zone: corpxyz.com |
| 10.10.10.1 | 10.10.10.1 | Zone: corpxyz.com | Zone: corpxyz.com |
| 10.10.10.1 | 10.10.10.1 | Zone: corpxyz.com | Zone: corpxyz.com |
| 10.10.10.1 | 10.10.10.1 | Zone: corpxyz.com | Zone: corpxyz.com |
| 10.10.10.1 | 10.10.10.1 | Zone: corpxyz.com | Zone: corpxyz.com |
| 10.10.10.1 | No data for vma | Zone: corpxyz.com | Zone: corpxyz.com |
| 10.10.10.1 | No data for vma | Zone: corpxyz.com | Zone: corpxyz.com |
| 10.10.10.1 | 10.10.10.1 | Zone: corpxyz.com | Zone: corpxyz.com |
| 10.10.10.1 | 10.10.10.1 | Zone: corpxyz.com | Zone: corpxyz.com |
| 10.10.10.1 | 10.10.10.1 | Zone: corpxyz.com | Zone: corpxyz.com |
| 10.10.10.1 | 10.10.10.1 | Zone: corpxyz.com | Zone: corpxyz.com |
| 10.10.10.1 | 10.10.10.1 | Zone: corpxyz.com | Zone: corpxyz.com |
| 10.10.10.1 | 10.10.10.1 | Zone: corpxyz.com | Zone: corpxyz.com |
| 10.10.10.1 | 10.10.10.1 | Zone: corpxyz.com | Zone: corpxyz.com |
| 10.10.10.1 | 10.10.10.1 | Zone: corpxyz.com | Zone: corpxyz.com |
To enable the appliance to automatically create DNS records, complete the following steps in Grid Manager:
For a new vDiscovery job: From the Data Management tab, select the IPAM tab, then select vDiscovery -> New from the Toolbar; or from the Cloud tab, select vDiscovery -> New from the Toolbar.
or
To modify an existing job: From the Data Management tab, select the IPAM tab and click vDiscovery -> Discovery Manager from the Toolbar, or from the Cloud tab, select vDiscovery -> Discovery Manager from the Toolbar. In the vDiscovery Job Manager editor, click the Action icon next to a selected job and select Edit from the menu.In step four of the vDiscovery Job wizard, or on the Data Consolidation tab of the vDiscovery Job Properties editor, complete the following:
For every newly discovered IP address, create: Select this checkbox to enable NIOS to automatically create or update DNS records for discovered VM instances if the records were originally created by vDiscovery.
Host: Select this to automatically create host records for discovered VMs.
A & PTR Record: Select this to automatically create A and PTR records for discovered VMs. Note that the DNS zones and reverse-mapping zones to which the records belong must exist in NIOS. Otherwise, vDiscovery does not create the records.
The DNS name will be computed from the formula: Enter the formula that NIOS uses to create FQDNs for discovered VMs. You can use the auto-generated FQDNs for DNS resolution purposes. You must use the syntax of ${parameter name} for this formula. For Azure, this field supports the vm_name and discovered_name parameters. For example, when you enter ${vm_name}.corp100.com and the discovered vm_name = XYZ, the DNS name for this IP becomes XYZ.corp100.com. When you enter ${discover_name} here and the discovered name for the IP is ip-172-31-1-64.us-west-1.compute.internal, the DNS name for this IP is ip-172-31-1-64.us-west-1.compute.internal
Note that if the ${vm_name} parameter of an instance contains any special character, the appliance will not be able to identify this instance and will convert it to a managed VM using the vm_id parameter.
Click Add(+).