redis_ippool module doesnot process lease_time in ack

[Chinnapaiyan, Nagamani]

redis_ippool module:

redis_ippool {
              #
              #  Note all configuration items at this level (above the redis block)
              #  are polymorphic, meaning xlats, attribute references, literal values
              #  and execs may be specified.
              #
              #  For example pool_name could be pool_name = 'my_test_pool' if only a
              #  single pool were being used.

              #
              #  Name of the pool to allocate leases from.
              #
              pool_name = &control:Pool-Name

              #
              #  How long a lease is reserved for after making an offer to the DHCP client
              #  if no value is provided, the value from lease_time is used for initial
              #  allocations.  No value should be provided for PPP/VPNs, this is mainly for
              #  the DORA flow in DHCP.
              #
              offer_time = 120

              #
              #  How long a lease is allocated for
              #
              lease_time = &reply:DHCP-IP-Address-Lease-Time

              #
              #  The device identifier, usually the Mac-Address but could be a combination
              #  of attributes, a user-name or a certificate serial number (if the number
              #  of sessions were limited to one per user/serial).
              #
              device = &DHCP-Client-Hardware-Address

              #
              #  The IP address being renewed or released
              #
              requested_address = "%{%{DHCP-Requested-IP-Address}:-%{DHCP-Client-IP-Address}}"

              #
              #  List and attribute where the allocated address is written to.
              #
              allocated_address_attr = &reply:DHCP-Your-IP-Address

              #
              #  List and attribute where the Pool-Range ID (if set) is written to.
              #
              #  The idea of the Pool-Range is that it provides a key into other datastores
              #  or caches, which store the additional options associated with the range an
              #  IP address belongs to.
              #
              #  There may be multiple ranges of IP address contained within any given pool,
              #  which is why this is provided in addition to the pool name.
              #
              range_attr = &reply:Pool-Range

              #
              #  If set - the list and attribute to write the remaining lease time to.
              #  This can be populated on alloc, or renew, if an IP address was available
              #  for the alloc.
              #
              expiry_attr = &reply:DHCP-IP-Address-Lease-Time

              #
              #  If true - Copy the value of ip_address to the attribute specified by
              #  reply_attr when performing an update/renew.  This is needed for DHCP where
              #  we need to send back DHCP-Your-IP-Address in ACKs.
              #
              copy_on_update = yes

              #
              #  Redis connection settings - Identical to all other Redis based modules.
              #
              redis {
                           server = devstack08-db-eval1-0001-001.oovb0g.0001.usw2.cache.amazonaws.com

                           pool {
                                         start = 0
                                         min = ${thread[pool].num_workers}
                                         max = ${thread[pool].num_workers}
                                         spare = 1
                                         uses = 0
                                         lifetime = 0
                                         retry_delay = 30
                                         idle_timeout = 60
                           }
              }
}

dhcp server:
recv DHCP-Request {
...
    update reply {
      &DHCP-IP-Address-Lease-Time = 3600
      &DHCP-Domain-Name-Server = 72.173.31.41
...
}

Regards,
Nagamani Chinnapaiyan