samba - Jan 2015 - Samba4 and 0.0.0.0:137 and 0.0.0.0:138 opened, why ? How do close it ?

I have Samba4 4.1.14 (built from sources) installed at Ubuntu 14.04 LTS x32
and acting as Standalone server at the time.
Here are 3 faces at Ubuntu: lo, lan and wan.
There are lines:
bind interfaces only = yes
interfaces = lo lan0
in smb.conf

But netstat -tulpn shows 0.0.0.0 binded address:
tcp         0      0 192.168.0.254:139         0.0.0.0:*
LISTEN      smbd
udp        0      0 192.168.0.255:137         0.0.0.0:*
nmbd
udp        0      0 192.168.0.254:137         0.0.0.0:*
nmbd
*udp       0      0 0.0.0.0:137 <http://0.0.0.0:137>
0.0.0.0:*                                  nmbd*
udp        0      0 192.168.0.255:138         0.0.0.0:*
nmbd
udp        0      0 192.168.0.254:138         0.0.0.0:*
nmbd
*udp       0      0 0.0.0.0:138 <http://0.0.0.0:138>
0.0.0.0:*                                  nmbd*

I don'n like *udp       0      0 0.0.0.0:port *at all !

Why is it so ?
How is it possible to close via Samba conf ?

Hello,

Am 11.01.2015 um 14:55 schrieb CpServiceSPb .:
> Here are 3 faces at Ubuntu: lo, lan and wan.
> There are lines:
> bind interfaces only = yes
> interfaces = lo lan0
> in smb.conf
> 
> But netstat -tulpn shows 0.0.0.0 binded address:
> tcp         0      0 192.168.0.254:139         0.0.0.0:*
> LISTEN      smbd
> udp        0      0 192.168.0.255:137         0.0.0.0:*
> nmbd
> udp        0      0 192.168.0.254:137         0.0.0.0:*
> nmbd
> *udp       0      0 0.0.0.0:137 <http://0.0.0.0:137>
> 0.0.0.0:*                                  nmbd*
> udp        0      0 192.168.0.255:138         0.0.0.0:*
> nmbd
> udp        0      0 192.168.0.254:138         0.0.0.0:*
> nmbd
> *udp       0      0 0.0.0.0:138 <http://0.0.0.0:138>
> 0.0.0.0:*                                  nmbd*
> 
> I don'n like *udp       0      0 0.0.0.0:port *at all !
> 
> Why is it so ?

The smb.conf man page answers this question  ('bind interfaces only'):

... nmbd also binds to the "all addresses" interface (0.0.0.0) on
ports
137 and 138 for the purposes of reading broadcast messages. If this
option is not set then nmbd will service name requests on all of these
sockets. If bind interfaces only is set then nmbd will check the source
address of any packets coming in on the broadcast sockets and discard
any that don't match the broadcast addresses of the interfaces in the
interfaces parameter list. ...




Regards,
Marc

Thanks for this answer.
As I understood, for example if parameter
bind interfaces only = yes is and
interfaces = lan0 (192.168.0.254) is

and if broadcast packet goes from 95.95.95.14 such packet will be dropped
(in other words) ?
Am I right ?

And other thing.
Why is 192.168.0.255 (network broadcast) opened for ?
May be exact such address (network broadcast) is inbtended for receiving
broadcasts ?
Within exact subnet but 0.0.0.0 is for all subnets ?

And is it possible to set off 0.0.0.0 via smb.conf ?


2015-01-11 17:24 GMT+03:00 Marc Muehlfeld <mmuehlfeld at samba.org>:
> Hello,
>
> Am 11.01.2015 um 14:55 schrieb CpServiceSPb .:
> > Here are 3 faces at Ubuntu: lo, lan and wan.
> > There are lines:
> > bind interfaces only = yes
> > interfaces = lo lan0
> > in smb.conf
> >
> > But netstat -tulpn shows 0.0.0.0 binded address:
> > tcp         0      0 192.168.0.254:139         0.0.0.0:*
> > LISTEN      smbd
> > udp        0      0 192.168.0.255:137         0.0.0.0:*
> > nmbd
> > udp        0      0 192.168.0.254:137         0.0.0.0:*
> > nmbd
> > *udp       0      0 0.0.0.0:137 <http://0.0.0.0:137>
> > 0.0.0.0:*                                  nmbd*
> > udp        0      0 192.168.0.255:138         0.0.0.0:*
> > nmbd
> > udp        0      0 192.168.0.254:138         0.0.0.0:*
> > nmbd
> > *udp       0      0 0.0.0.0:138 <http://0.0.0.0:138>
> > 0.0.0.0:*                                  nmbd*
> >
> > I don'n like *udp       0      0 0.0.0.0:port *at all !
> >
> > Why is it so ?
>
>
> The smb.conf man page answers this question  ('bind interfaces
only'):
>
> ... nmbd also binds to the "all addresses" interface (0.0.0.0) on
ports
> 137 and 138 for the purposes of reading broadcast messages. If this
> option is not set then nmbd will service name requests on all of these
> sockets. If bind interfaces only is set then nmbd will check the source
> address of any packets coming in on the broadcast sockets and discard
> any that don't match the broadcast addresses of the interfaces in the
> interfaces parameter list. ...
>
>
>
>
> Regards,
> Marc
>