nmblookup returns NULL mac Address from linux samba servers

Christopher R. Hertel crh at samba.org
Mon Aug 28 18:13:55 UTC 2017


This has always been the case, and it has nothing to do with the subnet of
the target machine.

The response to the status request message is generated by the responding
node, which has to retrieve the MAC address from the underlying hardware.
There is no standard way to do this across all of the system types on which
Samba runs (or, at least, that was the case when I first looked into this 18
years ago), so Samba just fills the value with zeros.

Again, this has nothing to do with the subnet on which the node is running.
It has everything to do with whether or not it is easy to retrieve the data
locally.

Chris -)-----

On 08/24/2017 05:30 AM, shivappa Sangapur via samba-technical wrote:
> Hi List,
> 
> When I was checking nmblookup utility, MAC address returned is always
> 00-00-00-00-00-00
> #nmblookup -A 192.168.10.10
> 
> Looking up status of 192.168.10.10
>         SHIVAPPAS     <00> -         H <ACTIVE>
>         SHIVAPPAS     <03> -         H <ACTIVE>
>         SHIVAPPAS     <20> -         H <ACTIVE>
>         SHIVAPPAS     <1e> - <GROUP> H <ACTIVE>
>         SHIVAPPAS     <00> - <GROUP> H <ACTIVE>
> 
>         MAC Address = 00-00-00-00-00-00
> 
> But there is one old thread on the same. The result is same even though
> samba server is on same subnet (execute nmblookup on same samba server.)
> https://lists.samba.org/archive/samba/1999-September/014495.html
> 
> This behavior is same in samba-4.5, 4.6.
> Can somebody help me to identify the cause.
> nmb->answers structure is always having 00000000 for mac address field.
> 
> Addition info: Windows clients return MAC address when nmblookup is executed
> for windows IP.
> 
> 
> Thanks & Regards,
> Shivappa
> 
> 
> 
> --
> View this message in context: http://samba.2283325.n4.nabble.com/nmblookup-returns-NULL-mac-Address-from-linux-samba-servers-tp4723151.html
> Sent from the Samba - samba-technical mailing list archive at Nabble.com.
> 



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