> ## Documentation Index
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> Use this file to discover all available pages before exploring further.

# About DNS Hostname SmartGroups

The DNS Hostname Resource Type in a SmartGroup enables you to filter non-TLS,
non-HTTP traffic (for example, SMTP and SSH) using the fully qualified domain
name (FQDN) of the target. The FQDN of the SmartGroup Resource Type is resolved
to its correct IP address.

<Note>
  You must enter the DNS Hostname resource type as a FQDN; entering just a hostname is not supported.

  The FQDN can only include characters that are valid in DNS hostnames. Wildcards
  are not supported.
</Note>

If you do not configure a custom DNS Server, any DCF rules that are executed that contain DNS hostnames are resolved to the Aviatrix Default DNS server.

If you decide to enter custom DNS Server information, the gateways that are part
of the DCF rule are updated to use the custom DNS Server information.

<Warning>
  If you want to filter web (TLS, HTTP, or HTTPS) traffic, Aviatrix strongly
  recommends configuring WebGroups instead of using the DNS Hostname Resource
  Type in a SmartGroup.
</Warning>

## Related Topics

* [Manage SmartGroups](/docs/cloud/resource-groups/smartgroup/smartgroups-about)
* [Create a SmartGroup](/docs/cloud/resource-groups/smartgroup/smartgroups-create)
* [Create a WebGroup](/docs/cloud/resource-groups/webgroups/webgroups-create)
* [DNS Server for Hostname Resolution](/docs/cloud/resource-groups/general/hostname-resolution-setting)


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