Comment 0 for bug 1853334

undercloud.conf
---------------
[DEFAULT]

templates = /home/centos/tripleo-heat-templates
container_images_file = /home/centos/containers-prepare-parameter.yaml

enable_routed_networks = true
enable_ui = false
overcloud_domain_name = localdomain
scheduler_max_attempts = 2
undercloud_ntp_servers = pool.ntp.org
undercloud_hostname = undercloud.rdocloud
local_interface = eth1
local_mtu = 1450
local_ip = fd12:3456:789a:1::1/64
undercloud_public_host = fd12:3456:789a:1::2
undercloud_admin_host = fd12:3456:789a:1::3
undercloud_nameservers = 8.8.8.8,8.8.4.4
local_subnet = ctlplane-subnet
subnets = ctlplane-subnet
ipv6_address_mode = dhcpv6-stateless

[ctlplane-subnet]
cidr = fd12:3456:789a:1::/64
gateway = fd12:3456:789a:1::fffe
dns_nameservers = fd12:3456:789a:1::1
inspection_iprange = fd12:3456:789a:1::aaaa,fd12:3456:789a:1::afff
masquerade = false

Reslting config:

[root@undercloud ~]# grep dhcp-range /var/lib/config-data/puppet-generated/ironic_inspector/etc/ironic-inspector/dnsmasq.conf
dhcp-range=set:ctlplane-subnet,fd12:3456:789a:1::aaaa,fd12:3456:789a:1::afff,64,10m

 ironic-inspector/dnsmasq.conf is configured for DHCPv6-stateful operation ^^. This is incorrect, the range should be:

 dhcp-range=set:ctlplane-subnet,::,static

From : dnsmasq(8) manual page:

 A static-only subnet with address all zeros may be used as a "catch-all" address to enable replies to all Information-request packets on a subnet which is provided with stateless DHCPv6, ie --dhcp-range=::,static