samba-mirror/docs-xml/smbdotconf/base/bindinterfacesonly.xml

<samba:parameter name="bind interfaces only"
                 type="boolean"
                 context="G"
                 xmlns:samba="http://www.samba.org/samba/DTD/samba-doc">
<description>
        <para>This global parameter allows the Samba admin 
        to limit what interfaces on a machine will serve SMB requests. It 
        affects file service <citerefentry><refentrytitle>smbd</refentrytitle>
        <manvolnum>8</manvolnum></citerefentry> and name service <citerefentry><refentrytitle>nmbd</refentrytitle>
        <manvolnum>8</manvolnum></citerefentry> in a slightly different ways.</para>

	<para>
	For name service it causes <command moreinfo="none">nmbd</command> to bind to ports 137 and 138 on the
	interfaces listed in the <smbconfoption name="interfaces"/> parameter. <command moreinfo="none">nmbd</command>
	also binds to the &quot;all addresses&quot; interface (0.0.0.0) on ports 137 and 138 for the purposes of
	reading broadcast messages.  If this option is not set then <command moreinfo="none">nmbd</command> will
	service name requests on all of these sockets. If <smbconfoption name="bind interfaces only"/> is set then
	 <command moreinfo="none">nmbd</command> 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
	<smbconfoption name="interfaces"/> parameter list.  As unicast packets are received on the other sockets it
	allows <command moreinfo="none">nmbd</command> to refuse to serve names to machines that send packets that
	arrive through any interfaces not listed in the <smbconfoption name="interfaces"/> list.  IP Source address
	spoofing does defeat this simple check, however, so it must not be used seriously as a security feature for
	 <command moreinfo="none">nmbd</command>.
	</para>

	<para>
	For file service it causes <citerefentry><refentrytitle>smbd</refentrytitle>
	<manvolnum>8</manvolnum></citerefentry> to bind only to the interface list given in the <smbconfoption
	name="interfaces"/> parameter. This restricts the networks that <command moreinfo="none">smbd</command> will
	serve, to packets coming in on those interfaces.  Note that you should not use this parameter for machines that
	are serving PPP or other intermittent or non-broadcast network interfaces as it will not cope with
	non-permanent interfaces.
	</para>

	<para>
	If <smbconfoption name="bind interfaces only"/> is set and the network address
	 <emphasis>127.0.0.1</emphasis> is not added to the <smbconfoption name="interfaces"/> parameter list
	 <citerefentry><refentrytitle>smbpasswd</refentrytitle> <manvolnum>8</manvolnum></citerefentry> may not
	 work as expected due to the reasons covered below.
	</para>

	<para>
	To change a users SMB password, the <command moreinfo="none">smbpasswd</command> by default connects to the
	 <emphasis>localhost - 127.0.0.1</emphasis> address as an SMB client to issue the password change request. If
	<smbconfoption name="bind interfaces only"/> is set then unless the network address
	 <emphasis>127.0.0.1</emphasis> is added to the <smbconfoption name="interfaces"/> parameter list then <command
	moreinfo="none"> smbpasswd</command> will fail to connect in it's default mode.  <command
	moreinfo="none">smbpasswd</command> can be forced to use the primary IP interface of the local host by using
	its <citerefentry><refentrytitle>smbpasswd</refentrytitle> <manvolnum>8</manvolnum></citerefentry>	<parameter
	moreinfo="none">-r <replaceable>remote machine</replaceable></parameter> parameter, with <replaceable>remote
	machine</replaceable> set to the IP name of the primary interface of the local host.
	</para>

</description>
<value type="default">no</value>
</samba:parameter>