OIT Network Systems

Current Visitor IP Address Assignments

This is a list of the current Visitor IP address assignments made by the OIT DHCP servers. For general information about VIP Service, see Visitor IP Service.

See the How to Interpret This Table section at the end of this document for information to help you interpret this data.

When Was This Document Updated?

This document is updated several times each hour; this one was produced at 2:46:04 pm Tue Sep 2 2014. It is based upon snapshots from the following OIT DHCP servers:

It typically takes up to 10 minutes for a new DHCP lease (or the renewal or expiration of an old DHCP lease) to be reflected below.


No Visitor IP addresses are currently assigned.



How to Interpret This Table

The table above shows all the leases for Visitor IP Addresses that have not yet expired. If all VIP Address leases have expired, no table will appear above.

Each row of the table describes a single Vistor IP address assignment (a.k.a "lease"). At the end of the table is the number of Visitor IP addresses currently assigned to customers, along with the total number of addresses allocated.

Only Visitor IP address assignments appear in this document. Assignments of static IP addresses, Mobile IP Addresses, TUD (Temporary Unregistered Dormnet) IP Addresses, and Temporary Visitor Wireless Network Access (TVWNA) IP Addresses do not appear.

If an OIT DHCP server is down (e.g. for planned maintenance or due to a failure), the most recent snapshot from it may not be "recent". You can judge for yourself how recent the data is by checking the section above entitled When Was This Document Updated. Snapshots that are "too old" are excluded from this document.

If no recent snapshot is available from a DHCP server, this document will not reflect the assignments granted by that server; assignments granted by other servers will still appear.

A device that has become ineligible for VIP Service may continue to appear in this document for several hours after becoming ineligible, until its final lease expires.

If a client obtains a lease on a VIP Address from one DHCP server, then before that lease expires, the client obtains a lease on another VIP Address from a different DHCP server, the client may appear above more than once.

Columns in Each Table

Client's Hardware Address
This is the hardware (e.g. Ethernet) address of the client's device.

Visitor IP Address and Hostname
The Visitor IP address that has been temporarily assigned to this client, as well as the Internet Hostname associated with this IP address.

VIP Service First Began
The date and time when this client first began receiving Visitor IP service.

VIP service is deemed to have ended when any of the following is true: the client is registered in the Host Database as an office machine, the client is subscribed to Dormnet service, the client receives Temporary Unregistered Dormnet (TUD) IP Service, the client receives Temporary Visitor Wireless Network Access (TVWNA), or the client is absent from Visitor IP service for six or more days.

If a VIP Service client has an unexpired lease at the time the client loses eligibility for VIP service (e.g. as a result of registering in the Host Database, or being declared ineligible for VIP service), that lease may continue to appear in this table until it expires, but this column will no longer accurately reflect when VIP service began. (It will instead reflect when this document was last updated.) This is a temporary condition, and will clear when the lease expires.

Lease Duration and Expiration Time
The length of this Visitor IP address assignment (a.k.a. "lease"), and when it expires.

If the client device remains attached to the same network, continues to use IP, and has correctly-working DHCP software, then before the lease expires the client will automatically attempt to renew (extend) its lease from the OIT DHCP server that granted the lease.

DHCP Server
The name of the OIT DHCP server that granted this lease.

OIT operates several DHCP servers to provide a measure of redundancy. Any of these servers can provide a new lease to a client; once a client has obtained a lease on a Visitor IP address, only the server that originally granted that lease can grant a renewal on it; the DHCP client is bound to this server.

Each DHCP server maintains its state across reboots or other failures; when the DHCP server restarts, any unexpired leases are still valid.

Because a DHCP client typically attempts to renew its lease halfway through its duration and will retry in the background until it succeeds or the lease expires, the client is not affected by a brief outage of the DHCP server to which it is bound. If a client is unable to renew its lease before it expires, the client loses the IP address, and must go through a discovery process to obtain a new one from any DHCP server (behavior on specific client platforms may vary).


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The Office of Information Technology,
Princeton University