To keep pace with the growing demand for IP addresses on the princeton-net subnet, the IP network range for that subnet will be expanded on July 18 2006.
princeton-net is a campus subnet present in the 87 Prospect Avenue Machine Room, the New South Machine Room, and 3 Puritan Court. (The subnet also has extensions to 171 Broadmead Street and the 87 Prospect Avenue Network Lab, both for test purposes.)
This campus subnet, once referred to as "the campus backbone network," is the network to which most central OIT servers are attached.
OIT will expand this subnet on July 18 2006. The expanded subnet will keep the same name, and all devices on it will keep their existing IP addresses, but the network's IP subnet mask will change.
People responsible for devices attached to princeton-net should cause these devices to switch to use a new subnet mask by September 1 2006. While most princeton-net devices can be changed at any time before that date, those devices running Windows should be changed "all at once" during 5:30 am - 7:00 am July 18.
People who maintain IP address access-lists (e.g. on firewalls or other appliances or servers, regardless of whether they are attached to princeton-net) that make reference to the subnet mask (or IP address range) of princeton-net should update those access-lists to use a new subnet mask (or IP address range) by September 1 2006.
Until July 18 2006, princeton-net is the subnet numbered 128.112.128.0/22; that is, the IP address range is 128.112.128.0 - 128.112.131.255. The subnet mask is 255.255.252.0, and the broadcast address is 128.112.128.0.
OIT is expanding this subnet on July 18 2006 by gluing to it the unused network 128.112.132.0/22 (i.e. IP address range 128.112.132.0 - 128.112.135.255).
Starting July 18 2006, the new princeton-net will be numbered 128.112.128.0/21; that is, the IP address range will be 128.112.128.0 - 128.112.135.255. The subnet mask changes to 255.255.248.0, and the broadcast address remains 128.112.128.0.
Devices currently registered in the Princeton University Host Database as homed on princeton-net will keep their IP addresses.
All devices attached to princeton-net should be switched to use the new subnet mask. We recommend that the person responsible for each of these devices do so by September 1 2006:
There are special concerns for Windows systems attached to princeton-net. Those devices should all be switched to use the new subnet mask at the same time. Thefore, we recommend all those systems switch to the new subnet mask during 5:30 am - 7:00 am July 18 2006. They should not be switched in advance, nor postponed to switch at a later date. During the period that these devices are in transition, some services provided by these systems may not work properly.
Anyone who has written an IP access list that specifies the old subnet mask for princeton-net (255.255.252.0) should update the access list to use the net subnet mask (255.255.248.0). This should be done before September 1 2006. (This can even be done before July 18 2006.) Such IP access lists might be found on devices such as firewalls and servers that restrict client access by IP address; the device need not be attached to princeton-net to be affected by the change.