diff --git a/README.md b/README.md
index 3181faf..644e8d6 100644
--- a/README.md
+++ b/README.md
@@ -70,6 +70,7 @@ No modules.
 | <a name="input_database_subnetpool_id"></a> [database_subnetpool_id](#input_database_subnetpool_id) | The id of the subnetpool to create the databse network from.<br>Since this module can route private subnets to the backbone, it needs to make sure it's not creating overlapping subnets. | `string` | `null` | no |
 | <a name="input_external_network_id"></a> [external_network_id](#input_external_network_id) | The id of the external network to connect the frontend router to. | `string` | `null` | no |
 | <a name="input_frontend_subnet_prefix_len"></a> [frontend_subnet_prefix_len](#input_frontend_subnet_prefix_len) | The prefix length of the frontend subnet. Must be between 20 and 32. | `number` | `24` | no |
+| <a name="input_network_internal_domain_name"></a> [network_internal_domain_name](#input_network_internal_domain_name) | The domain name to use for dns resolution inside the private networks | `string` | `null` | no |
 | <a name="input_project_domain"></a> [project_domain](#input_project_domain) | The domain where this project will be created | `string` | `"default"` | no |
 | <a name="input_project_name"></a> [project_name](#input_project_name) | The name of the project | `string` | n/a | yes |
 | <a name="input_project_tags"></a> [project_tags](#input_project_tags) | The tags to append to this project | `list(string)` | `[]` | no |
diff --git a/main.tf b/main.tf
index aec813d..63f8457 100644
--- a/main.tf
+++ b/main.tf
@@ -42,6 +42,7 @@ resource "openstack_networking_subnetpool_v2" "database" {
 resource "openstack_networking_network_v2" "frontend" {
   count          = var.architecture_tiers > 0 ? 1 : 0
   name           = "${local.resource_prefix}-frontend-network"
+  dns_domain     = var.network_internal_domain_name
   description    = "Terraform managed."
   tenant_id      = data.openstack_identity_project_v3.this.id
   shared         = false
@@ -52,6 +53,7 @@ resource "openstack_networking_network_v2" "frontend" {
 resource "openstack_networking_network_v2" "backend" {
   count          = var.architecture_tiers > 1 ? 1 : 0
   name           = "${local.resource_prefix}-backend-network"
+  dns_domain     = var.network_internal_domain_name
   description    = "Terraform managed."
   tenant_id      = data.openstack_identity_project_v3.this.id
   shared         = false
@@ -62,6 +64,7 @@ resource "openstack_networking_network_v2" "backend" {
 resource "openstack_networking_network_v2" "database" {
   count          = var.architecture_tiers == 3 ? 1 : 0
   name           = "${local.resource_prefix}-database-network"
+  dns_domain     = var.network_internal_domain_name
   description    = "Terraform managed."
   tenant_id      = data.openstack_identity_project_v3.this.id
   shared         = false
diff --git a/tests/module/README.md b/tests/module/README.md
index 39d0f93..8785b30 100644
--- a/tests/module/README.md
+++ b/tests/module/README.md
@@ -47,6 +47,7 @@
 | <a name="input_database_subnetpool_cidr_blocks"></a> [database_subnetpool_cidr_blocks](#input_database_subnetpool_cidr_blocks) | The CIDR blocks for the database subnet pool | `list(string)` | <pre>[<br>  "192.168.8.0/23"<br>]</pre> | no |
 | <a name="input_database_subnetpool_id"></a> [database_subnetpool_id](#input_database_subnetpool_id) | The id of the subnetpool to create the databse network from.<br>Since this module can route private subnets to the backbone, it needs to make sure it's not creating overlapping subnets. | `string` | `null` | no |
 | <a name="input_frontend_subnet_prefix_len"></a> [frontend_subnet_prefix_len](#input_frontend_subnet_prefix_len) | The prefix length of the frontend subnet. Must be between 20 and 32. | `number` | `24` | no |
+| <a name="input_network_internal_domain_name"></a> [network_internal_domain_name](#input_network_internal_domain_name) | The domain name to use for dns resolution inside the private networks | `string` | `null` | no |
 | <a name="input_project_domain"></a> [project_domain](#input_project_domain) | The domain where this project will be created | `string` | `"default"` | no |
 | <a name="input_project_tags"></a> [project_tags](#input_project_tags) | The tags to append to this project | `list(string)` | `[]` | no |
 | <a name="input_public_nameservers"></a> [public_nameservers](#input_public_nameservers) | A list of public DNS servers to upstreams requests to in your subnets.<br>This is not necessary if your openstack deployment already has configured default upstreams for neutron. | `list(string)` | `[]` | no |
diff --git a/tests/module/variables.tf b/tests/module/variables.tf
index 89032c6..1a1c878 100644
--- a/tests/module/variables.tf
+++ b/tests/module/variables.tf
@@ -70,6 +70,12 @@ variable "database_subnetpool_cidr_blocks" {
 }
 
 #! networking variables
+variable "network_internal_domain_name" {
+  type        = string
+  description = "The domain name to use for dns resolution inside the private networks"
+  default     = null
+}
+
 variable "frontend_subnet_prefix_len" {
   type        = number
   description = "The prefix length of the frontend subnet. Must be between 20 and 32."
diff --git a/variables.tf b/variables.tf
index 648d06b..2fdf404 100644
--- a/variables.tf
+++ b/variables.tf
@@ -79,6 +79,12 @@ variable "database_subnetpool_cidr_blocks" {
 }
 
 #! networking variables
+variable "network_internal_domain_name" {
+  type        = string
+  description = "The domain name to use for dns resolution inside the private networks"
+  default     = null
+}
+
 variable "frontend_subnet_prefix_len" {
   type        = number
   description = "The prefix length of the frontend subnet. Must be between 20 and 32."