Hi Pablo,
I see 2 options.
First, if the upgrade path is supported (check the installation guide, for example, you can upgrade 6.2, 6.3 or 7.0 to 7.1, but 6.1 or before requires intermediate upgrade : http://www.cisco.com/en/US/docs/net_mgmt/network_registrar/7.1/installation/guide/IGoverv.html#wp1061412)
Then a standard upgrade will keep the lease database. You can also copy the data directory of the current CNR to the server on which you will install 7.1 and it will pick up the database and upgrade it. If upgrade path is not supported, you will need to do intermediate upgrades (upgrade 5.5 to 6.1, then 6.3 then 7.1).
Second option, if you only want to keep the lease database, not the configuration, you can export it from the current server and import it in the new server like this:
On the old server:
nrcmd> export leases -server leaseout.txt
On the new server:
nrcmd> import leases leaseout.txt
Before you can import leases, you must:
1. Configure scopes in the DHCP server for the leases to be imported, using the scope command.
2. If the host names for the leases are to be dynamically entered in DNS as part of the import, configure zones in the DNS server to allow DNS updates, using the zone name enable dynamic command.
3. Set the DHCP server to import mode so that it does not respond to other lease requests during the lease importing, using the dhcp enable import-mode command.
4. After the leases are imported, take the DHCP server out of import mode so that it will respond to other lease requests, using the dhcp disable import-mode command.
Tom
