[Samba] Internal DNS update behavior / scavenging records

[James]

Hello,

     I'm noticing if a client changes IP's. It registers it's new IP but 
doesn't update the existing record. So what I see is two A records for 
the same client but with different IP's in the Microsoft DNS snap in 
tool. Shouldn't the client update it's existing record and not create a 
new one? Is this considered normal behavior at the moment?

Samba 4.1.13
Ubuntu 12.04

# Global parameters
[global]
         workgroup = DOMAIN
         realm = DOMAIN.LOCAL
         netbios name = PFDC1
         server role = active directory domain controller
         dns forwarder = 8.8.8.8
         idmap_ldb:use rfc2307 = yes

         # Debug Logging Information
         log level = 3
         log file = /usr/local/samba/var/logs/log.%m
         max log size = 2000

         # Don't allow any updates | allow unsigned updates | only allow 
signed updates (False | nonsecure | signed)
         allow dns updates = signed

         #Disable CUPS Printing
         load printers = No
         printcap name = /dev/null
         disable spoolss = Yes

[netlogon]
         path = /usr/local/samba/var/locks/sysvol/domain.local/scripts
         read only = No
         oplocks = No
         level2 oplocks = No

[sysvol]
         path = /usr/local/samba/var/locks/sysvol
         read only = No
         oplocks = No
         level2 oplocks = No

-- 
-James