OIT Static IP Service provides a static (unchanging) IP address and DNS hostname to your computer when it is attached to OIT Ethernet Service on its "home network."
A computer's "home network" is defined as the IP network (a.k.a. "subnet") specified in the computer's Princeton University Host Database entry. Some networks span multiple buildings; conversely, some buildings contain several networks. For a list of buildings and networks, see the Princeton Network ("subnet") List.
As no device is permitted to be homed on the network providing OIT Wireless Service, OIT Static IP Service is not available to clients using OIT Wireless Service. Such clients instead use OIT Mobile IP Service.
If you have questions about the procedures below, or encounter difficulties related to them, please contact the OIT Help Desk for assistance.
The following procedures apply to all computers attached to the campus network:
E.g. if your computer is in any of these modes, then before attaching a Ethernet cable or activating its Wireless interface, first wake up your computer, shut it down entirely, then attach the cable, and finally start up your computer.
By shutting down entirely, you are less likely to make the mistake of later re-attaching your computer to a network cable (or via its wireless interface) while the computer is powered-on or sleeping. (And you'll also avoid needing to wake up a sleeping computer just so you can power it down before re-attaching it to networking wiring.)
To use OIT Static IP service, your computer must meet the following requirements:
OIT normally recommends that most devices be configured to use OIT DHCP Service to learn their IP configuration. For a device that cannot (or should not) rely on DHCP, OIT normally recommends that it be configured to use OIT BootP Service to learn its IP configuration. For a device that cannot (or should not) use either DHCP or BootP, you will have to configure the device's IP information manually.
If you choose to configure your device to obtain its IP configuration via OIT DHCP Service, your device must meet the the eligibility requirements for that service. Similarly, if you choose to configure your device to obtain its IP configuration via OIT BootP Service, your device must meet the eligibility requirements for that service. See OIT DHCP and BootP Services for a description of both services and their eligibility requirements.
For currently-supported platforms, documentation published by the OIT Help Desk normally shows how to configure the device to use OIT DHCP Service.
If you choose to configure your device to obtain its IP configuration manually, you should be aware that OIT does not publish detailed documentation for manually configuring IP settings on specific platforms, as this is not normally a recommended configuration. You may need to consult technical documentation that came with your platform (e.g. operating system). In addition, you will need (at least) the information that appears in Default IP Routers, Network Masks, and Broadcast Addresses. You may also need the information in OIT Domain Name Service (DNS).
When the interface visits another network, it will not be able to use OIT Static IP Service on that network. (If the device is eligible for OIT Mobile IP Service, and if OIT Mobile IP Service is available on the network the interface is visiting, the interface will receive OIT Mobile IP Service for the duration of the visit.)
Those IP subnets appear only in the Host Database, but in fact do not correspond to any "real" physical network on campus. When you see an IP address in the Host Database that is one of these networks, you are not looking at an OIT Static IP Address. These IP addresses instead simply act as "placeholders" in a Host Database entry, indicating that a network interface speaks IP, but has no OIT Static IP Address assigned.
Since these networks do not correspond to any physical network on campus, it is impossible to connect such a network interfaces to its "home" network. Any network the interface is attached to will be a network other than the interface's home network, so the interface will not receive OIT Static IP Service on that network. (If the device is eligible for OIT Mobile IP Service, and if OIT Mobile IP Service is available on the network the interface is visiting, the interface will receive OIT Mobile IP Service for the duration of the visit.)
(An explanation of the purpose of recyclenet appears in OIT Static IP Recycling Facility (SIRF). An explanation of the purpose of wirelessnet appears in OIT Wireless Service. A driftnet IP address is assigned to the Ethernet interface of a Dormnet suscription when the customer has indicated s/he wants that interface to not receive OIT Static IP Service, but instead to rely solely on OIT Mobile IP Service.
For devices meeting the requirements above, OIT Static IP service works as follows:
Assuming you have correctly entered the IP configuration, the IP configuration will work as long as your device is attached to its "home network."
If you relocate your device to a network other than its "home network", this IP configuration will not work there.
If your device meets the eligibility requirements for OIT Mobile IP Service, it may instead use that service while visiting another network; you would need to reconfigure the device to obtain its IP configuration via DHCP. If use of OIT Mobile IP Service is not feasible or desirable, to obtain IP service in the new location, you would need to update the Host Database entry to reflect the device's new "home network", and reconfigure your device with the new IP configuration, so you may use OIT Static IP Service while attached to that new network. (The latter approach is not feasible for a Dormnet subscription; by definition a Dormnet subscription's Ethernet interface is homed on the pu-dormnet-bb (aka "Dormnet) network, and its Wireless interface (if any) is homed on the wirelessnet (OIT Wireless Service) network. The Ethernet interface may use IP service outside of pu-dormnet-bb only by using OIT Mobile IP Service; the Wireless interface may use IP service only by using OIT Mobile IP Service.)
Manual configuration is not feasible for a device's network interface attached via OIT Wireless Service. OIT Static IP Service is not available to clients using OIT Wireless Service. The wirelessnet IP address that appears in devices' Host Database entries are simply placeholders; a device manually configured to use a wirelessnet IP address will not work.
Manual configuration is not feasible for a device's network interface that is registered in the Host Database as being homed on recyclenet. The recyclenet IP address that appears in the device's Host Database entry is simply a placeholder; a device manually configured to use a recyclenet IP address will not work. If you wish to use manual configuration, first change the Host Database entry to replace the recyclenet IP address with one on the network to which the device is actually attached.
Manual configuration is not feasible for a device's network interface that is registered in the Host Database as being homed on driftnet. The drifnet IP address that appears in the device's Host Database entry is simply a placeholder; a device manually configured to use a drifnet IP address will not work. If you wish to use manual configuration, first change the Host Database entry to replace the driftnet IP address with one on the network to which the device is actually attached.
If you relocate your device to a network other than its "home network", OIT BootP Service will not provide it with an IP configuration.
If your device meets the eligibility requirements for OIT Mobile IP Service, it may instead use that service while visiting another network; you would need to reconfigure the device to obtain its IP configuration via DHCP. If use of OIT Mobile IP Service is not feasible or desirable, to obtain IP service in the new location, you would need to update the Host Database entry to reflect the device's new "home network", so you may use OIT Static IP Service while attached to that new network. (The latter approach is not feasible for a Dormnet subscription; by definition a Dormnet subscription's Ethernet interface is homed on the pu-dormnet-bb (aka "Dormnet) network, and its Wireless interface (if any) is homed on the wirelessnet (OIT Wireless Service) network. The Ethernet interface may use IP service outside of pu-dormnet-bb only by using OIT Mobile IP Service; the Wireless interface may use IP service only by using OIT Mobile IP Service.)
BootP configuration is not feasible for a device's network interface attached via OIT Wireless Service. OIT Wireless Service relies on OIT Mobile IP Service, which in turn relies on DHCP (not BootP).
BootP configuration is not feasible for a device's network interface that is registered in the Host Database as being homed on recyclenet. If you wish to use BootP configuration, first change the Host Database entry to replace the recyclenet IP address with one on the network to which the device is actually attached.
BootP configuration is not feasible for a device's network interface that is registered in the Host Database as being homed on driftnet. If you wish to use BootP configuration, first change the Host Database entry to replace the driftnet IP address with one on the network to which the device is actually attached.
If you relocate your device to a network other than its "home network", and if your device meets the eligibility requirements for OIT Mobile IP Service, it will use that service. OIT DHCP Servers will assign ("lease") to the interface an OIT Mobile IP address and Internet hostname, and provide your device with an appropriate IP configuration for the network it is visiting.
While the University is fortunate to have a large number of IP addresses suitable for assignment as OIT Static IP Addresses, the number is still finite. If not actively managed, shortages can become an issue.
When an entry is deleted from the Host Database, any OIT Static IP Addresses in the entry are reclaimed by OIT:
Sometimes the Technical Contacts responsible for an office device forget to remove the entry from the Host Database after the device has been retired.
The OIT Static IP Recycling Facility (SIRF) detects when an OIT Static IP Address has not used on the campus network for a long time. It recycles those IP addresses, so they may be re-assigned. This helps the University preserve a supply of IP addresses.
When a new Host Database entry is created for a Dormnet subscription (a.k.a. a "Dormnet Host Database entry"), it is created with no IP addresses.
( Prior to April 2 2008 , when a new Host Database entry was created for a Dormnet subscription, it was created with a pu-dormnet-bb OIT Static IP Address assigned to the first interface (the interface identified in the Host Database as the device's "Ethernet" interface). And Dormnet Host Database entry in the Host Database which was in the "unsubscribed" state on that date was also modified to remove any IP addresses in the entry.)
When a Dormnet Host Database entry is subscribed, the first interface (the interface identified in the Host Database as the device's "Ethernet" interface) is assigned an IP address, if one has not already been assigned. The IP address is assigned is a pu-dormnet-bb OIT Static IP Address. It is not possible to assign this interface an OIT Static IP Address on any other subnet; all Dormnet subscriptions are "homed" on pu-dormnet-bb (the network used for OIT Ethernet Service in all dormitories, eating clubs, and apartments) because the subscription is intended to provide service to personally-owned student devices.
Each Dormnet Host Database entry may optionally have one wireless interface registered as well. This is normally registered as the entry's second interface. The Host Database will assign this interface a wirelessnet IP address. This is not an OIT Static IP Address. It acts as a placeholder, indicating the network interface speaks IP, but has not OIT Static IP Address assigned. When the network interface is attached to the network, even to OIT Wireless Service, it will not receive OIT Static IP Service. It will receive OIT Mobile IP Service (assuming the device is eligible for OIT Mobile IP Service, and is attached to a network where OIT Mobile IP Service is available).
When a Host Database entry for a Dormnet subscription is unsubscribed, all IP addresses in the Host Database entry are removed from the entry. If the Host Database entry is later resubscribed to Dormnet, new IP address(es) are assigned.
Our service supports devices with multiple network interfaces, for example, a computer with one Ethernet interface homed on one network, and another Ethernet interface homed on another network.
Each network interface that is eligible for OIT Static IP Service is treated separately. Each has its own "home network." Each is is independently eligible to use BootP or DHCP (if you choose to configure the interface to use either of those services).
Therefore, each such interface is independently eligible for Mobile IP Service. It is possible that one interface (attached to its home network) may be using OIT Static IP Service at the same time that the other interface (attached to a network other than its home network) may be using OIT Mobile IP Service.
If your device is assigned more than one IP address in the Host Database, then OIT inserts all of these IP addreses into DNS as belonging to your device's hostname. (One exception is that IP addresses on the wirelessnet network are never inserted into DNS, as they are only placeholders intended to indicate that the interface is registered for use with OIT Wireless Service.) A DNS lookup for the IP addressses associated with your device's hostname will return all of these IP addresses. A DNS lookup for the name associated with any of these IP addresses will return your device's canonical hostname.
If you have questions or need assistance with any of the procedures in this document, please contact the OIT Help Desk.