diff --git a/ansible/kolla-bifrost.yml b/ansible/kolla-bifrost.yml
index 4ddda432a..acda10647 100644
--- a/ansible/kolla-bifrost.yml
+++ b/ansible/kolla-bifrost.yml
@@ -9,6 +9,7 @@
       # Network configuration.
       kolla_bifrost_dhcp_pool_start: "{{ provision_oc_net_name | net_inspection_allocation_pool_start }}"
       kolla_bifrost_dhcp_pool_end: "{{ provision_oc_net_name | net_inspection_allocation_pool_end }}"
+      kolla_bifrost_dhcp_pool_mask: "{{ provision_oc_net_name | net_mask }}"
       kolla_bifrost_dnsmasq_router: "{{ provision_oc_net_name | net_inspection_gateway or provision_oc_net_name | net_gateway }}"
       kolla_bifrost_dnsmasq_dns_servers: "{{ resolv_nameservers | default([]) }}"
       kolla_bifrost_domain: "{{ resolv_domain | default }}"
diff --git a/ansible/roles/kolla-bifrost/defaults/main.yml b/ansible/roles/kolla-bifrost/defaults/main.yml
index 93dfc35c3..ae2e5fa47 100644
--- a/ansible/roles/kolla-bifrost/defaults/main.yml
+++ b/ansible/roles/kolla-bifrost/defaults/main.yml
@@ -30,6 +30,7 @@ kolla_bifrost_extra_kernel_options: []
 # IP address range for DHCP.
 kolla_bifrost_dhcp_pool_start:
 kolla_bifrost_dhcp_pool_end:
+kolla_bifrost_dhcp_pool_mask:
 
 # Default route provided to nodes via DHCP.
 kolla_bifrost_dnsmasq_router:
diff --git a/ansible/roles/kolla-bifrost/templates/kolla/config/bifrost/bifrost.yml b/ansible/roles/kolla-bifrost/templates/kolla/config/bifrost/bifrost.yml
index e8accf4f6..7ec8bf873 100644
--- a/ansible/roles/kolla-bifrost/templates/kolla/config/bifrost/bifrost.yml
+++ b/ansible/roles/kolla-bifrost/templates/kolla/config/bifrost/bifrost.yml
@@ -11,6 +11,7 @@ extra_kernel_options: "{{ kolla_bifrost_extra_kernel_options if kolla_bifrost_ex
 # IP address range for DHCP.
 dhcp_pool_start: "{{ kolla_bifrost_dhcp_pool_start }}"
 dhcp_pool_end: "{{ kolla_bifrost_dhcp_pool_end }}"
+dhcp_pool_mask: "{{ kolla_bifrost_dhcp_pool_mask }}"
 
 {% if kolla_bifrost_dnsmasq_router %}
 # Default route provided to nodes via DHCP.
diff --git a/releasenotes/notes/bifrost-dhcp-range-netmask-fd40642967042267.yaml b/releasenotes/notes/bifrost-dhcp-range-netmask-fd40642967042267.yaml
new file mode 100644
index 000000000..4083af8c3
--- /dev/null
+++ b/releasenotes/notes/bifrost-dhcp-range-netmask-fd40642967042267.yaml
@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Ironic inspection through Bifrost now work even if DHCP-relay is used.
+    The dhcp-range in dnsmasq.conf corrctly configured with network mask.