Configuring ACLs and Split-Horizon
Split-horizon DNS allows for different DNS records to be provided for the same domain, depending on the source of the DNS query. For example, if a server has both a private IP address (such as on a local area network) and a public address, using split-horizon DNS with an access control list (ACL), the same name can direct to either the private IP address or the public one based on the client sending the query. This may also allow for improved network latency for local networks.
Access Control Lists (ACLs)
The ACL module applies the specified network lists to the in the configuration for zones inside the group and the servers that belongs to the group, when exporting the group or zone.
ACLs may be created under each DNS Group, accessed from the DNS tab DNS Groups sub-tab.
Expand the Group that you want the view applied to, and then expand the section "Applied ACLs" by clicking on the expansion arrow to the right of the section name.
If ACLs already exist, they will be shown under this section.
To add a new list, click the "Add or Edit ACL" button.
If no ACLs currently exist, the dialog will only show inputs for ACL Name and ACL Networks - enter a Name and Network and click "Save Changes".
If previous ACLs exist, a "Create or Edit" selector will be be available.
Since we are creating a new ACL, just keep this at the default value ("Create New ACL"), and enter in the Name and Network(s) for the new ACL. Separating multiple CIDRs with a comma (,).
When done, save the ACL by clicking "Save changes". The new ACL will be added to the Group's "Attach ACL" list. Choose the ACL from the dropdown and click "Attach".
Edit an ACL
ACLs may be edited similarly to how they are created. Click the "Add or Edit ACL" button under the "Applied ACLs" module for the DNS Group.
Select the ACL you wish to edit from the "Create or Edit" selector. Then, edit the Name or Network fields as desired.
When done, click "Save Changes".
Detach an ACL from a Group
Detaching an ACL removes it from the Group, but the ACL will still exist for re-use in other Groups.
To detach an ACL, expand the "Applied ACLs" section under the desired Group, and click on the "Detach" button under the "Actions" column.
The ACL will be removed from under the Group, but will remain in other Groups it exists under, as well as be selectable from the "Add ACL" window and "Attach ACL" dropdown.
Delete an ACL
ACLs may be deleted through the "Edit ACL" interface. Click the "Add or Edit ACL" button under the "Applied ACLs" module for the DNS Group.
Select the ACL you wish to delete from the "Create or Edit" selector. Then, click the red "Delete" button under the Networks field.
The ACL will be permanently deleted, and will no longer show under any Groups to which it has been attached, nor show in the "Existing ACLs" list.
Add an existing ACL to another Group
Existing ACLs may be added to as many Groups as desired. If ACLs already exist, clicking the "Add or Edit ACL" button will give an additional option to "Create New".
To select a previously created ACL, select it from the "Attach ACL" dropdown and click "Attach".
Configuring Split-Horizon Views
In ProVision, DNS Groups are used to organize split-horizon views with applied ACLs to determine which DNS records are applied to a zone for a given requestor. One zone may be cloned between two or more DNS groups, ACL(s) applied, and separate zone records customized for each cloned zone.
1 ) Create DNS Group(s)
Create DNS Groups, or verify that DNS Groups already exist, for both the default response and each split zone view that is needed.
In this example, we will use ProVision's Default Group for the default response, and "Another Group" for an additional split zone view.
2) Add Zone to Groups
Create or add the DNS Zone to both the Default response group and the additional group(s) intended for the split zone view(s).
Clone Existing Zone
You can quickly add the same zone to multiple groups by using "Clone Existing Zone" in the Add Zone modal, or the "Add to Group" button from the Zone View page!
Clone Existing:
From the DNS Group container, click "Add Zone", then select "Clone Existing Zone" under "Populate type".
Add from Zone View Page:
Click the green + to create the zone under another DNS Group.
3) Add ACL(s) to the Group(s)
Create and/or add the ACL to the group(s) that will route to the alternate DNS records.
4) Add or Edit DNS Zone Records
Click the zone name from either DNS Group to open the Zone View page and verify that the desired DNS Group tab is selected at the top of the module.
Under the DNS Records Section, click "Add" to create a new zone record, or click on an existing record to edit its values according to the split view needs.
At this point, the split-horizon view set up is complete, and you may further adjust DNS Group or Zone / Record details as needed.
Additional Information
For additional information on working in DNS, see the following sections: