zero free leases

[Koichi Mori]

Hello,

"David W. Hankins" <David_Hankins at isc.org> wrote
in article Re: zero free leases 
at Thu, 28 Jun 2007 12:58:09 -0700
>The state change may not be getting acknowledged for many reasons;
>
>1) Servers not communicating - not in 'normal' state.  Extended
>   runtime even in communciations-interrupted state will not reclaim
>   leases.

I have some questions. 
Is it in specification of ISC DHCP server?
Dose it work well DHCP?
failover MUST 2 servers be working? 

I thought failover is duplicate system of DHCP.
Usually duplicate system is still working when other side be down.
#same as both systems are working.

This specification means "If you use failover, ISC DHCP doesn't work
well when a server to be down" dosen't it?

I hope(need) failover work same as both server working when other
side be down.

-- 
Koichi Mori