diff --git a/doc/source/reference/bare-metal/ironic-guide.rst b/doc/source/reference/bare-metal/ironic-guide.rst
index d5624e7f65..349bb2c5d3 100644
--- a/doc/source/reference/bare-metal/ironic-guide.rst
+++ b/doc/source/reference/bare-metal/ironic-guide.rst
@@ -17,14 +17,15 @@ Enable Ironic in ``/etc/kolla/globals.yml``:
 
    enable_ironic: "yes"
 
-In the same file, define a network interface as the default NIC for dnsmasq,
-a range of IP addresses that will be available for use by Ironic inspector,
-as well as a network to be used for the Ironic cleaning network:
+In the same file, define a network interface as the default NIC for dnsmasq and
+a range of IP addresses that will be available for use by Ironic inspector.
+The optional netmask of the network should be provided in case when DHCP-relay
+is used. Finally, define a network to be used for the Ironic cleaning network:
 
 .. code-block:: yaml
 
    ironic_dnsmasq_interface: "eth1"
-   ironic_dnsmasq_dhcp_range: "192.168.5.100,192.168.5.110"
+   ironic_dnsmasq_dhcp_range: "192.168.5.100,192.168.5.110,255.255.255.0"
    ironic_cleaning_network: "public1"
 
 In the same file, optionally a default gateway to be used for the Ironic
diff --git a/etc/kolla/globals.yml b/etc/kolla/globals.yml
index d7c89b774e..c813782549 100644
--- a/etc/kolla/globals.yml
+++ b/etc/kolla/globals.yml
@@ -595,8 +595,8 @@
 #############################
 # dnsmasq bind interface for Ironic Inspector, by default is network_interface
 #ironic_dnsmasq_interface: "{{ network_interface }}"
-# The following value must be set when enabling ironic,
-# the value format is "192.168.0.10,192.168.0.100".
+# The following value must be set when enabling ironic, the value format is
+# "192.168.0.10,192.168.0.100,255.255.255.0" the last being an optional netmask.
 #ironic_dnsmasq_dhcp_range:
 # PXE bootloader file for Ironic Inspector, relative to /tftpboot.
 #ironic_dnsmasq_boot_file: "pxelinux.0"
diff --git a/tests/templates/globals-default.j2 b/tests/templates/globals-default.j2
index 94ef7683d3..72d74067fa 100644
--- a/tests/templates/globals-default.j2
+++ b/tests/templates/globals-default.j2
@@ -103,7 +103,7 @@ enable_aodh: "yes"
 
 {% if scenario == "ironic" %}
 enable_ironic: "yes"
-ironic_dnsmasq_dhcp_range: "10.42.0.2,10.42.0.254"
+ironic_dnsmasq_dhcp_range: "10.42.0.2,10.42.0.254,255.255.255.0"
 {% endif %}
 
 {% if scenario == "masakari" %}