Hostnames
Version: 1.4
Last Modified: 2004 January 22
Every computer on the Case network must have a hostname assigned to it. That
hostname may be of the computer owner's choosing, subject to some
restrictions. If you choose a user-specified hostname, there is no guarantee
that you will receive the name you have requested nor is there a guarantee that
you may keep the name for your entire duration using
the Case network.
Automatically-assigned hostnames
Every device on the network will have a hostname automatically assigned
when that device is registered. These hostnames are selected to
be unique on the network. For many computers, the automatically-assigned
hostname is satisfactory and there is no need to select a different
hostname. However, some computer owners may wish to select a
different hostname for their systems. This document describes
the rules covering hostname selection for computers and other devices
attached to the Case network.
To change the hostname of a computer registered to you, use the
Self-service Hostname Change page.
Only the person to whom a computer is
registered may change that computer's hostname. If the person
responsible for a computer has changed since the computer was
registered, contact hostmaster at
hostmaster@case.edu
to update the computer's registration.
Other useful tools to check and modify hostnames are available at the
Network
Tools page.
Use of the correct registered hostname is mandatory
Once a hostname is assigned to a computer, whether automatically or
by request, the computer must use that hostname for all protocols
used on the Case network: TCP/IP and Microsoft Networking.
Although some of these protocols make it easy to pick
arbitrary computer names, use of the registered hostname is
mandatory.
The reason for using the registered hostname for a computer system
(and all protocols being used on the system) is that using a hostname
not assigned to the computer can cause severe operational
problems with other computers on the network. Because of this
possibility, a computer may be disconnected from the Case network until
it is properly configured to use the registered hostname
as its name in any protocol.
It is a good idea, when considering possible hostnames, to select
one that is compatible with every protocol you expect to use on
your computer. The hostname selected for DNS
use will also be used for the Windows networking hostname.
Domains used for hostnames
Host names for all machines on the 129.22 network (the Case network)
must be in one of the subdomains of .case.edu. Users may
not register their own domains for machines on the Case network.
Conversely, all hostnames in the .case.edu domain must resolve to an
IP address in 129.22, unless by prior arrangement with ITS.
The hostnames of all student-owned computers are in the .student.case.edu
domain. There are no exceptions.
TCP/IP hostnames for all faculty and staff computers are in the
domain used for the department with which the faculty or staff
member is affiliated.
Changing a hostname
A hostname may be changed as often as desired using the
Hostname Change form.
Note, however, that there is a delay before a hostname change takes effect.
Hostnames are assigned on strictly a first-come, first-served basis.
A hostname cannot be assigned to, nor "reserved" for, a computer that
is not yet registered on the Case network.
The unique part of the hostname must be between 1 and 15 characters.
For example, in the hostname, b61524.student.case.edu, the hostname has the
following parts:
- b61524 - Unique hostname
- student - Subdomain
- case.edu - Domain
Only letters (a-z), digits (0-9), and hyphens (-) are allowable
characters. The hostname must start with a letter and end with a
letter or digit (no hyphens). Note that the Internet
Domain Name System (DNS) is not case sensitive:
"john.student.case.edu" is equivalent to "John.student.case.edu" and
even "JoHn.StudEnT.CaSe.EDU".
The following hostnames, among others, are not available for assignment:
- The names of all Internet Standard, Proposed Standard, and Draft
protocols, and the names of those protocols followed by a number.
- "cwru", "ns", and "po"; alone or with a numeric suffix.
- All the subdomain names under *.case.edu.
- Any name that could collide with the automatically-generated names.
In other words, any name consisting of one of the prefixes used for
automatically-assigned hostnames followed by 3 to 5 digits.
- Any name that is in the wrong format for the Internet Domain Name
System.
In addition, ITS maintains a list of hostnames that may not be assigned.
Resolution of disputes
When two or more people want the same hostname, they are strongly
encouraged to negotiate with one another to reach a mutually
agreeable result. Technology Infrastructure Services does not adjudicate hostname
disputes.
All Case policies apply
You are expected to exercise good judgement and maturity when
considering a hostname that might be offensive. All hostnames
chosen must comply with all University policies, including all
ethics policies. The standard University disciplinary processes
for students, faculty, and staff apply.
This policy may be changed at any time, as needed.
