Can't Get Dynamic Address from one pool when device is configured as Fixed Address on other, separate pool.

[Graham Clinch]

> The /20:
> 
> subnet 130.x.x.0 netmask 255.255.240.0 {
> 	option subnet-mask 255.255.224.0 ; 
> 	option routers 130.x.x.1 ; 
> 	option domain-name-servers 10.x.x.x , 10.x.x.x ; 
> 	option domain-name "example.com" ; 
> 	option netbios-name-servers 10.x.x.x ; 
> 	option netbios-node-type 8 ; 
>  	default-lease-time 86400 ;
> 	get-lease-hostnames False ;
> 	max-lease-time 86400 ;
> 	min-lease-time 500 ;
> 	ping-check True ;
> 	ping-timeout 2 ;
> 	pool {
> 		option subnet-mask 255.255.224.0 ; 
> 		option routers 130x.x.1 ; 
> 		option domain-name-servers 10.x.x.x , 10.x.x.x ; 
> 		option domain-name "example.com" ; 
> 		option netbios-name-servers 10.x.x.x ; 
> 		option netbios-node-type 8 ; 
> 		 authoritative ;
> 		ddns-updates False ;
> 		default-lease-time 1800 ;
> 		do-forward-updates False ;
> 		get-lease-hostnames False ;
> 		max-lease-time 1800 ;
> 		min-lease-time 1800 ;
> 		one-lease-per-client True ;
> 		ping-check True ;
> 		ping-timeout 2 ;
> 		update-optimization True ;
> 		use-host-decl-names False ;
> 		 allow unknown-clients ;
> 
> And the 'Dynamic' /24:
> 
> subnet 137.x.x.0 netmask 255.255.255.0 {
>  	pool {
> 		option subnet-mask 255.255.255.0 ; 
> 		option routers 137.x.x.1 ; 
> 		option domain-name-servers 137.x.x.x ; 
> 		 authoritative ;
> 		ddns-updates False ;
> 		default-lease-time 1800 ;
> 		do-forward-updates False ;
> 		get-lease-hostnames False ;
> 		max-lease-time 1800 ;
> 		min-lease-time 1800 ;
> 		one-lease-per-client True ;
> 		ping-check True ;
> 		ping-timeout 2 ;
> 		update-optimization True ;
> 		use-host-decl-names False ;
> 		 allow unknown-clients ;
> 		range 137.x.x.30 137.x.x.254;

Urgh.  That configuration is crying out for some housekeeping!

I'm heading down the same track as Phil - my *hunch* is that 'allow
unknown-clients' in the /24 is preventing known clients from being
allocated addresses (allow 'only' unknown-clients).

The documentation isn't very clear, but given that "Dynamic address
assignment to unknown clients is allowed by default" (in dhcpd.conf's
"The unknown-clients keyword"), I'd start by removing both occurances of
"allow unknown-clients", since specifying it is either doing nothing, or
(my hunch) implicitly causing 'deny known-clients'.

It Just Works For Us(TM) with no allow/deny statements anywhere (and
we're using failover to boot).

Bonus nit: The subnet mask option for 130.x... is a /19, but that
subnet's netmask definition is for a /20.


Graham

-- 
Graham Clinch
Systems Programmer,
Lancaster University