Overcloud deploy fails because undercloud does not reply DHCP Offer packet

Issue

• openstack overcloud deploy command fails with the following error message.

  [overcloud-ComputeSriov-aaaaaaaaaa-6-aaaaaaaaaa.ComputeSriov]: CREATE_FAILED  ResourceInError: resources.ComputeSriov: Went to status ERROR due to "Message: Exceeded maximum number of retries. Exhausted all hosts available for retrying build failures for instance aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa., Code: 500"
  [overcloud-ComputeSriov-aaaaaaaaaa-6-aaaaaaaaaa.ComputeSriov]: DELETE_IN_PROGRESS  state changed
  [overcloud-ComputeSriov-aaaaaaaaaa-6-aaaaaaaaaa.ComputeSriov]: DELETE_COMPLETE  state changed
  [overcloud-ComputeSriov-aaaaaaaaaa-6-aaaaaaaaaa.ComputeSriov]: CREATE_IN_PROGRESS  state changed
  [overcloud-ComputeSriov-aaaaaaaaaa-6-aaaaaaaaaa.ComputeSriov]: CREATE_FAILED  ResourceInError: resources.ComputeSriov: Went to status ERROR due to "Message: Exceeded maximum number of retries. Exhausted all hosts available for retrying build failures for instance bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb., Code: 500"
  [overcloud-ComputeSriov-aaaaaaaaaa-6-aaaaaaaaaa.ComputeSriov]: DELETE_IN_PROGRESS  state changed
  [overcloud-ComputeSriov-aaaaaaaaaa-6-aaaaaaaaaa.ComputeSriov]: DELETE_COMPLETE  state changed
  [overcloud-ComputeSriov-aaaaaaaaaa-6-aaaaaaaaaa.ComputeSriov]: CREATE_IN_PROGRESS  state changed
  [ComputeSriov]: UPDATE_FAILED  UPDATE aborted (Task update from ResourceGroup "ComputeSriov" [cccccccc-cccc-cccc-cccc-cccccccccccc] Stack "overcloud" [dddddddd-dddd-dddd-dddd-dddddddddddd] Timed out)
  [overcloud-ComputeSriov-aaaaaaaaaa]: UPDATE_FAILED  Stack UPDATE cancelled
  [overcloud]: UPDATE_FAILED  Timed out
  [overcloud-ComputeSriov-aaaaaaaaaa-6-aaaaaaaaaa]: UPDATE_FAILED  Stack UPDATE cancelled
  [overcloud-ComputeSriov-aaaaaaaaaa.6]: UPDATE_FAILED  resources[6]: Stack UPDATE cancelled
  [overcloud-ComputeSriov-aaaaaaaaaa]: UPDATE_FAILED  Resource UPDATE failed: resources[6]: Stack UPDATE cancelled
  
   Stack overcloud/dddddddd-dddd-dddd-dddd-dddddddddddd UPDATE_FAILED
  
  overcloud.ComputeSriov.6:
    resource_type: OS::TripleO::ComputeSriov
    physical_resource_id: eeeeeeee-eeee-eeee-eeee-eeeeeeeeeeee
    status: UPDATE_FAILED
    status_reason: |
      resources[6]: Stack UPDATE cancelled
  

• Packet capture shows multiple retransmitted DHCP Discover packets, and undercloud doesn't reply DHCP Offer packets.

  aa:aa:aa:aa:aa:aa > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 389: 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from aa:aa:aa:aa:aa:aa, length 347
  aa:aa:aa:aa:aa:aa > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 389: 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from aa:aa:aa:aa:aa:aa, length 347
  aa:aa:aa:aa:aa:aa > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 389: 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from aa:aa:aa:aa:aa:aa, length 347