Static IP Address Guidelines

If you are the IP network administrator for your unit, or if you have been given the task of assigning hostnames and IP addresses, please read this carefully.

IP Addresses

Each computer at Michigan State University (and elsewhere on the Internet) is assigned a unique IP address. In most cases, the computer is also assigned a unique hostname. This name and address allow you to communicate with other computer systems on campus and on the Internet.

Addresses and names can be assigned in one of two ways – static (permanent) or dynamic (temporary, e.g., DHCP). This document deals with static IP address assignments and hostnames only. (Further information on dynamic addresses for Ethernet – DHCP.)

Each unit on campus that maintains static IP addresses is responsible for designating an IP network administrator to work with MSU Information Technology. The IP network administrator needs to keep a record of all static IP addresses that are assigned, including (at a minimum) the address, the host (computer) name, and the location of the computer.

It’s important to submit a USS form for IP address or DNS hostname updates on a regular basis. While there is not a requirement to submit this information, you are strongly urged to do so, as it can often aid MSU IT, the unit’s network managers, and the end-users. Also, note that some computer systems may require that IP addresses and hostnames be registered in this way before a connection can be made.

IP Network Administrator Responsibilities

Each unit on campus should have a designated IP network administrator, whose function is to maintain records of static IP address assignments within the unit and to pass on communications related to the campus network to individuals within the unit. Read more about DNS updates in the Domain Name Guidelines.

For academic units, this can be handled at the college level, department level, or both. For smaller administrative units, this can be relegated to the parent unit or to the department that provides computer support for the unit.

The IP network administrator will also be the contact person for communication from MSU IT about network issues, either pertaining to the campus network at large or pertaining to specific issues related to computer systems within the unit.

Generally, the IP network administrator would be the department’s primary network manager or system administrator. In some cases, this task may fall to an administrative assistant or another employee classification.

To request a change to the IP network administrator for a unit, or to designate an IP network administrator for a new unit, use the IP Address or DNS hostname update form.

Obtaining & Assigning IP Addresses

The IP address is a four-part, dotted-decimal number, with each of the four components consisting of a number from 0 to 255. The IP network administrator for a given unit is assigned one or more ranges of IP addresses for use within a particular building or computer network.

The first three parts are fixed according to your unit’s location within the Internet at large and within the campus network. The last part is your assigned range and is usually 2-253 or a portion of that. The IP addresses ending in 0, 1, 254, and 255 are reserved for various network uses.

Types of IP Addresses

IP addresses may be obtained for the following classes of use.

  • Full Internet access: This is the default, and covers most IP addresses at MSU. These IP addresses will provide full Internet access to and from a workstation or server.
  • Limited access, campus-only: IP addresses may be obtained which are restricted to campus-wide access. These would generally be assigned for the use of printers or other network devices, where control or access is required between buildings on campus. No access either to or from the Internet at large is available for these IPs.
  • Limited access, local building network: IP addresses may be obtained which are limited to the local network only. These would be applicable for printers or other devices where the controlling server is located within the same building. Note: Most buildings have several subnets, for the staff (administrative) network, the classroom/public network, computer labs (operated by MSU IT), and/or the residence hall room network. In some cases, departments may have separate subnets from each other within a building. The IP addresses in this category will not communicate between subnets within the building.

If you wish for other levels of access control (e.g., limiting inbound access but allowing full outbound access, restricting access by service or port), you will need to run a firewall. (Learn more about firewall options.)

Assigning IP Addresses

You can assign any of your registered addresses to any server, workstation, or network device within your unit, but ONLY within the same building and subnet. You may want to group by system type (e.g., primary servers with low numbers), and/or location (by floor, work group, etc.). Keep in mind, though, that any good numbering scheme will not last forever, and the best approach is to keep good records.

Obtaining Additional IP Addresses

If you need additional IP addresses or need IP addresses for a new building or a new portion of your building network, use the IP Address or DNS hostname update form. Please indicate the anticipated number of IP addresses that will be needed and the building or section of the network for the needed addresses.

Domain (Host) Names

Domain names are assigned to various entities within a network. Generally, a domain name will provide a mapping to the IP address of a computer system or server. Domain names may also be used to map to mail system names (the portion following the “@” in an email address, server, or service names, and names for other networked devices (routers, switches, printers, etc.). Read more in the Domain Name Guidelines.

A computer system generally has a primary domain (host) name, which is a unique name assigned within the campus unit. The full domain name (hostname) is generally a four-part name of the form “sysname.unit.msu.edu” where you pick “sysname” and “unit” is the department or unit code that has been assigned to your unit. Five-part (or longer) domain names are permissible if desired to subdivide the domain names within a given unit. The name “unit.msu.edu” itself may also be assigned to a unit’s key server (file server or web server, generally), and to a unit’s mail server, which may or may not be the same as the file/web server.

“Sysname” must be an alphanumeric string, although it may have a dash (-) in it, but NOT an underscore (_). A sysname is a maximum of 63 characters in length, although 12-16 characters is a more practical length. For PCs and other workstations, you may want to name it after the person (e.g., last name, initials), or the location (e.g., vc-a215-2). For host computers, you’ll want something mnemonic or else something memorable.

A computer system may have one or more additional domain names, either as aliases (CNAMEs) or as additional “host” (A) records. These would generally be used to describe additional services (e.g., web, email, FTP). Additional names may also be used for “virtual hosts” (especially for web servers) or to allow for a domain name change.