Data Center IP Addressing Standard

The University Data Center (UDC) network architecture provides a highly available, redundant network. It requires IP addresses to be allocated differently than they may have been in the past or elsewhere on campus. The architecture requires two additional IP addresses for the routers on each subnet, used by Hot Standby Router Protocol to provide layer 3 redundancy. In some circumstances two additional IP addresses will be required for those choosing to utilize firewall services.

• For all new subnets created, the first five addresses are reserved for network use.
• For existing subnets, the first five and the last two IP addresses are reserved for network use. Reserved means that if systems on those addresses are retired, no new systems should be assigned to them. The addresses should not be re-used.
• The minimum subnet size is /27.

When relocating existing servers to the UDC, UDC network engineers assess each subnet and determine whether any changes are necessary. If changes are necessary, you will be able to choose the least disruptive changes to allocate the additional IP addresses (first five or last two addresses). Subnets not utilizing firewall services, or not in a manner requiring address allocations, will not need to re-allocate firewall addresses.