<samba:parameter name="bind interfaces only" type="boolean" context="G" advanced="1" wizard="1" developer="1" 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 "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 <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> and <citerefentry><refentrytitle>swat</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> <para> The <command moreinfo="none">swat</command> status page tries to connect with <command moreinfo="none">smbd</command> and <command moreinfo="none">nmbd</command> at the address <emphasis>127.0.0.1</emphasis> to determine if they are running. Not adding <emphasis>127.0.0.1</emphasis> will cause <command moreinfo="none"> smbd</command> and <command moreinfo="none">nmbd</command> to always show "not running" even if they really are. This can prevent <command moreinfo="none"> swat</command> from starting/stopping/restarting <command moreinfo="none">smbd</command> and <command moreinfo="none">nmbd</command>. </para> </description> <value type="default">no</value> </samba:parameter>