How do I change a hostname?

To change a hostname, enter your changes in the DNS database. You must be listed in the database as a NetAdmin for your subnets or domains to enter changes. If necessary, a registered NetAdmin can add you to the authorization list or you can request to be added by sending an email to hostmaster@cornell.edu.

Can I change a host name without having to delete and recreate all its aliases?

Yes. The DNS Database's batch interface includes a chghost command that moves a host name and all of its attributes to a new IP address; a chgname command that replaces one host name with another, keeping all of the attributes; and a delhost command that removes a host name and all its associated CNAME and MX records. The batch interface also has other commands to simplify DNS maintenance.

Can I register my webpage, "http://webhost.cit.cornell.edu/mypages/page1"?

No, there is no way to map an IP address to a specific subdirectory on a website. You can register the hostname part, which is the machine on which the web site resides, but we cannot put an entry into DNS that will point to a particular directory on that machine. This must be done with "virtual hosting."

How do I register a virtual host?

A virtual host is usually registered as a CNAME (alias). An excellent explanation and resource for virtual hosting is available at Apache's own site.

What about DHCP (Dynamic Host Configuration Protocol)?

This protocol was developed with the idea that there would be a server on the network that would "hand out" IP addresses and configurations of individual machines. You can set this up on your own subnet, or use CIT's campus-wide DHCP service. 

I made my changes on the host page; why aren't they showing up already?

Changes to the DNSDB database are uploaded to the campus DNS servers every hour at the top of the hour, so it could take up to one hour for your changes to appear (depending on when you make them).

Someone has joined/left our network administration group. Can you add/remove this person on our subnet and domain pages?

Anyone with permissions to change DNS entries for your networks/domains can add or remove net admins. Go to the subnet inspect/modify page for each subnet and remove the NetID and email address of the person or people leaving your department. Then, go to the domain inspect/modify page and do the same for any domains in your department. These changes will take effect immediately.