[Samba] DHCP Updates to DNS - Multiple Entries with Same IP

Rowland penny rpenny at samba.org
Wed May 20 09:54:50 UTC 2020

On 19/05/2020 22:29, Mark Petersen via samba wrote:
> I'm having difficulties with dhcpd updating DNS entries.
> When I look in DNS in my Forward Lookup Zone via Windows 10 I have multiple A Host records with the
> same ip address but the names are like this:
> Aarons-iPad Host(A) static
> Aarons-iPadCNF:134dd19a-e0fd-4230-8108-40b4ae3328d9 Host(A) static
> Aarons-iPadCNF:156181c7-c420-409d-ab88-40c56f6b1c88 Host(A) static
The 'CNF' is short for 'collision', multiple things are trying to update 
the record at the same time, first one wins, the rest get marked with 
the 'CNF'.
> Also,note that on Ubuntu 18.04 aarch64, isc-dhcp-server runs as
> dhcpd:dhcpd
I just found out that Debian 10 now uses 'dhcpd' as well ;-)
> This seems to be happening with iphone/ipads (wireless) but also HP printers that are all wired.

It looks like your clients are trying to update their own records, you 
only need the script if some or all of your clients cannot update their 
own records, but, if you use the script, you must stop the clients from 
trying to update their own records.


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