DHCP failover lease balancing with nearly saturated pools

David W. Hankins David_Hankins at isc.org
Thu Jan 29 00:53:43 UTC 2009

On Wed, Jan 28, 2009 at 04:53:37PM -0600, Jack Kielsmeier wrote:
> The primary server hands out leases, and the pools on busy subnets are
> balanced every 5 minutes or so. When there is only one lease left, the
> secondary won't balance that lease over to the primary.

This is because there's an odd number of leases remaining.  If each
server opted to 'round up' from 0 to 1 lease to give away to the
peer, then in this (and other) cases, they would never stop giving 1
lease to each other to try and balance the pool every go round.

Failover isn't really well designed for the case where the servers
don't see all the broadcast traffic, I don't really have an easy
answer for that.

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
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 194 bytes
Desc: not available
URL: <https://lists.isc.org/pipermail/dhcp-users/attachments/20090128/60b79535/attachment.bin>

More information about the dhcp-users mailing list