3.8. Setting a Nameserver on the Undercloud's Neutron Subnet

Overcloud nodes require a nameserver so that they can resolve hostnames through DNS. For a standard Overcloud without network isolation, the nameserver is defined using the Undercloud's neutron subnet. Use the following commands to define the nameserver for the environment: 
$ neutron subnet-list
$ neutron subnet-update [subnet-uuid] --dns-nameserver [nameserver-ip]
View the subnet to verify the nameserver: 
$ neutron subnet-show [subnet-uuid]
+-------------------+-----------------------------------------------+
| Field             | Value                                         |
+-------------------+-----------------------------------------------+
| ...               |                                               |
| dns_nameservers   | 8.8.8.8                                       |
| ...               |                                               |
+-------------------+-----------------------------------------------+

Important

If you aim to isolate service traffic on to separate networks, the Overcloud nodes use the DnsServer parameter in your network environment templates. This is covered in the Advanced Overcloud scenario in Section 6.2.6.2, “Creating an Advanced Overcloud Network Environment File”.