I already have 300 hosts registered in DNS, how can I upload them into DHCP?
You have three options:
- Option 1: You can batch delete the hosts,
forcing each system go through the registration process.
All systems will receive new
IP addresses within the static range.
- Option 2: Obtain the MAC addresses for the registered systems.
If you've been keeping track of this for internal purposes, you
should have a list of IP and MAC addresses that you can batch load
into the DNS registration at
http://dnsdb/dnsdb-cgi/batch.pl.
Each line in the file should contain:
- the word "addmac"
- the IP Address
- the MAC Address.
Use spaces as delimiters. For example:
addmac 192.64.0.35 00:44:55:ab:cd:ef
- Option 3: Wait for the self-update web page that
will allow users to fill in network registry data for an
existing DNS registration. This will be available
sometime in the summer of 2004.
What happens to leases in each pool over time?
The default lease timeout is 1 hour for dynamic pools and 5 minutes for registration pools. Once assigned a lease, the computer can continue to renew the lease indefinitely. Or if the lease is not renewed, the IP address will be re-assigned to a new computer for a new lease.
Does my IP number stay with my hostname?
Once registered in the DNSDB database, the IP number becomes a static address and remains
with the given hostname. Network administrators can change the name
or address within the DNSDB database.
What happens if I install a new computer on a subnet that has DHCP registration?
- Open a web browser.
- Your browser will automatically be directed to the registration
page; if you don't see the registration page, go to http://dhcp-reg.cit.cornell.edu/.
- Accept the hostname, it will likely be your NetID or NetID-1.
- Restart your computer, or drop and renew your DHCP lease.
What happens if I change a network adapter on a subnet that has DHCP registration?
If the netadmin does not update the MAC field for that host in the
DNSDB database, then it will look like a new computer and go through
the registration process.
I have an off-campus visitor who needs an address for a few days; how
can I use DHCP to give them access to the network?
You can enable visitor registration on your subnet, with or without
a passcode, and either register the visitor's computer yourself or
have the visitor use the self-registration form.
See the Network Registration for Cornell Visitors page.
Find out more: