Periodically use "cnrFailoverConfig -compare" or WebUI in CNR 6.0 and above to check to make sure there are no differences.
Network topology changes or IP address allocation changes can make it necessary for clients to get a different address. You must plan for a period of time when some clients on a subnet have an address from the old range and some have renewed and gotten an address from the new range. You can reduce the amount of time during which both sets of addresses are active by reducing the length of leases before you make the change so that all of the clients have short-duration leases. This ensures that they must renew their leases frequently and therefore pick up a lease from the new range soon after you make the change. Be sure not to set the lease time so short that leases run out while you stop and start the server to make the change. After you have made the change, be sure to restore the original lease period so that you do not increase the load on the server
