Summary and Problem Description
-------------------------------
The in.dhcpd(1M) server assumes that there will be one subnet per
physical interface on a Solaris box.  This assumption causes problems
for applications and network topologies that require configuring
multiple subnets per physical interface and leaves our dhcp server at
a competitive disadvantage to other 3rd party offerings, such as ISC's
dhcp server.  This RFE will correct this by modifying the in.dhcpd to
recognize and configure more than one subnet address per interface.
The server will then be able to manage leased addresses and respond to
client requests on these multiple subnets.


Release Binding
---------------
Patch/micro	- For all but the default change
Minor		- For the default value change


Changes to in.dhcpd
------------------
The server will be modified to read the interface table and include
logical interfaces that represent additional subnets on the physical
interface.  These subnets will be configured as part of a shared
network.  Client requests received on the physical interface will have
no indication for which subnet the clients are destined.  From an
administrator's perspective, assignment of addresses will be
arbitrary.  In an attempt to distribute addresses evenly, a "round
robin" method of assignment will be used.  This occurs only on a new
assignment, and not on renewal of an existing lease.

The in.dhcpd '-i' option
--------------------------
The 'in.dhcpd -i' option will be modified to allow logical interfaces
of the format, <interface>:x (e.g. hme0:1).

Changes to /etc/inet/dhcpsvc.conf file
--------------------------------------
A new keyword, SHARED_NETWORKS, will be added to dhcpsvc.conf that
will indicate whether this feature should be enabled or disabled with
a value of TRUE of FALSE.  This will default to FALSE for the
patch/micro binding for strict compatibility, and will change to TRUE
for the next minor release.

The keyword, INTERFACES, will be modified to include logical
interfaces in the list of interfaces to listen to.


Impact of changes
-----------------
These changes to the server will affect existing dhcp server
installations in the following way.  An existing installed in.dhcpd
server configured with multiple subnets on a single physical interface
will start listening for requests on those subnets that were
previously ignored.  Since this maybe an undesirable effect, the
SHARED_NETWORKS keyword will be added with a default to FALSE for
patch releases.  The default will be TRUE in the next minor release.
(A future case may remove the keyword itself entirely.)


What will not be included
-------------------------
The subnet option that is described in RFC 3011 will not be included
with this RFE.  The subnet option could be used by clients to control
the subnets to which subnets they are assigned.  This is not a
requirement for this project and can be done at a later time.


Interface Table

The following interfaces will be modified by the solution above.

Interface       Classification       Comments
------------------------------------------------------------------------
in.dhcpd -i     Evolving             Modified to include logical
                                     interfaces.
------------------------------------------------------------------------
INTERFACES      Evolving             INTERFACES keyword in dhcpsvc.conf
                                     updated to accept logical
                                     interfaces.
------------------------------------------------------------------------
SHARED_NETWORK	Unstable             Added to /etc/inet/dhcpsvc.conf.
------------------------------------------------------------------------