silently neglected requests fixed by restarting dhcpd

[David W. Hankins]

On Tue, May 09, 2006 at 02:44:29PM -0400, Gordon A. Lang wrote:
> Solaris 10 running dhcpd version 3.0.3 in a "whole root zone," which is 
> Sun's terminology for their virtual-machine-like technology that is standard 
> with Solaris 10.
> host address 192.168.104.11 (with 32 bit netmask) bound to a loopback 
> interface on Solaris box.
> static route on routers direct 192.168.104.11/32 packets to the server's 
> native address, which is 10.104.0.11.
> two local routers running HSRP on all layer-3 interfaces, plus one router at 
> each remote site.
> all routers have "ip helper-address 192.168.104.11" configurations on all 
> VLAN's.

Mm.

=== Quoting the 3.0.4 readme:

                               SOLARIS

One problem which has been observed and is not fixed in this
patchlevel has to do with using DLPI on Solaris machines.  The symptom
of this problem is that the DHCP server never receives any requests.
This has been observed with Solaris 2.6 and Solaris 7 on Intel x86
systems, although it may occur with other systems as well.  If you
encounter this symptom, and you are running the DHCP server on a
machine with a single broadcast network interface, you may wish to
edit the includes/site.h file and uncomment the #define USE_SOCKETS
line.  Then type ``make clean; make''.  As an alternative workaround,
it has been reported that running 'snoop' will cause the dhcp server
to start receiving packets.  So the practice reported to us is to run
snoop at dhcpd startup time, with arguments to cause it to receive one
packet and exit.

        snoop -c 1 udp port 67 > /dev/null &

=== end quote


I take it to mean that some event causes the DLPI device to stop
being able to receive packets...probably a bug in our DLPI
implementation.  I think I have patches queued somewhere that I
thought were feature enhancements.  I'll have to have a look to
make sure I queued those right.

Back to your problem...

I suggest in the network you describe (loopback aliased globally
routable ip address is the only way the dhcp server is reached),
you might want to recompile the dhcpd with USE_SOCKETS defined,
and then in dhcpd.conf set the 'local-address' statement to the
loopback alias (192.168.104.11).

So instead of using DLPI at all, the server binds a normal UDP
socket to that address only.  So long as it only ever gets to talk
to clients either via unicast UDP or via relay agents, it should
all just work.

-- 
David W. Hankins		"If you don't do it right the first time,
Software Engineer			you'll just have to do it again."
Internet Systems Consortium, Inc.		-- Jack T. Hankins