> ## Documentation Index
> Fetch the complete documentation index at: https://docs.aviatrix.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Groups Settings

> Configure the DNS server used for hostname resolution in Groups

On the Groups > Settings tab, you can configure the DNS Server for Hostname
Resolution.

## DNS Server for Hostname Resolution

When a Distributed Cloud Firewall (DCF) rule attempts a DNS match because of the
included DNS Hostname SmartGroup, the Aviatrix Default DNS server is used to
resolve the DNS, unless you configure a custom DNS Server.

<Note>
  You should select the DNS server to use before [adding a DNS Hostname
  SmartGroup](/docs/cloud/resource-groups/smartgroup/smartgroups-reference#create-new-smartgroup-reference)
  to a DCF rule.
</Note>

To select a DNS server:

1. In Aviatrix PaaS, go to *Groups > Settings*.
2. Select one of the following on the DNS Server for Hostname Resolution card:

* Gateway's Management DNS Server: This is the Aviatrix default DNS server.
* Custom DNS Servers: Enter one or more custom DNS server addresses (maximum is
  two) that will be updated for all enforcing gateways.

<Note>
  Ensure the correctness of the custom DNS server addresses before saving. Any
  valid IP address is accepted by this field, even if it is not the IP address
  of a DNS server.
</Note>

2. Click *Save*.

## Related Topics

* [Create a SmartGroup](/docs/cloud/resource-groups/smartgroup/smartgroups-create)
* [About DNS Hostname SmartGroups](/docs/cloud/resource-groups/smartgroup/hostname-smartgroups-about)


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