host-identifier option dhcp6.client-id can't work

[larry.lai]

Dear all,
Does anyone get  the problem that "host-identifier option 
dhcp6.client-id" can't work.
My dhcpd version  is 4.2.0a1 on Ubuntu 9.04.
My dhclient version  is 4.1.1rc1 on Ubuntu 8.04.

My client uses the fixed DUID-LL by  hard-coded lease file.
The content is just one line -
default-duid "\000\003\00\001\001\002\003\004\005\006";.

I uses the following configuration on the server side.
....
host xxhost{
    host -identifier option dhcp6.client-id 00:03:00:01:01:02:03:04:05:06;
    fixed-address6 2001:db8:0:1::127;
}
subnet6 ...
....

The client always pick up the address from the subnet6 pool not from 
"host xxhost".
Both changing the dhcp6.client-id to the client's mac or the DUID mac , 
01:02:03:04:05:06, still doesn't work.

I sniffer the packet between the client and the server.
I'm really sure the DUID is  00:03:00:01:01:02:03:04:05:06;
 From the configuration sample with the dhcpd package, dhcp6.client-id  
contains whole client identifier header except for the option type field 
and the option length field.
Is there any limitation when we usg "host -identifier option 
dhcp6.client-id" ?
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 From the official site, it said "The "host-identifier" option is 
limited to a simple token."
What does it means? Is there any example?
##############################################################
Does anyone know what the problem is ?

Sincerely,
Larry.Lai