coordinating multiple DHCP servers?

[Glenn Satchell]

>Date: Fri, 12 Oct 2007 15:29:32 -0700
>From: "James Hartley" <jjhartley at gmail.com>
>To: dhcp-users at isc.org
>Subject: coordinating multiple DHCP servers?
>
>I am attempting to coordinate multiple DHCP servers.
>
>Upon selection of an IP address to assign to a client, is it
>guaranteed that a DHCP server will send out an ARP request to
>determine whether the IP address is already in use?
>
>If a DHCP server has a pool defined for 100 leases & all 100 leases
>have been assigned, will the DHCP server ignore the 101th request for
>a lease?
>
>One scheme to coordinate multiple DHCP servers is to further segment
>the subnet.  ie.  assuming two servers are used, one server might
>allocate addresses from the upper half of the subnet while the other
>allocates addresses from the lower half.  Yet if sufficient end
>devices exist on the subnet & the one server goes down, the other may
>not be able to honor all lease requests.  Is there a better heuristic
>for coordinating multiple DHCP servers such that one doesn't issue an
>IP address already been allocated by another?
>
>Any insight which can be shared would be greatly appreciated.
>
>Thanks.
>
>Jim

Hi Jim

Have you read the dhcpd.conf man page section titled "DHCP FAILOVER"?
The ISC dhcp server includes a builtin functionality to allow two
servers to communicate and share lease information.

regards,
-glenn