Private IP networks are "organizationally scoped" IP nets which the University of Michigan uses internally but are not routed outside the institution. This is consistent with the Address Allocation for Private Internets (RFC1918).
| Prefix | First Address | Last Address | Number of Addresses |
|---|---|---|---|
| 10.0.0.0/8 | 10.0.0.0 | 10.255.255.255 | 16,777,216 |
| 172.16.0.0/12 | 172.16.0.0 | 172.31.255.255 | 1,048,576 |
| 192.168.0.0/16 | 192.168.0.0 | 192.168.255.255 | 65,536 |
University of Michigan Private IP Assignments
Historically, the University has scoped the organization for private IP address on the Ann Arbor campus, and this is divided between the two core network providers, ITS and HITS. Some specifics include:
- Each group is responsible for the administration of prefixes within its assigned ranges.
- A range of IP space designated as “shared” may be routed between core networks.
- Ranges designated as “local” will not be routed between core networks.
- One block of private IP space (172.31.0.0/17) is routable between the ITS core network and Dearborn.
- One block of private IP space (172.31.128.0/17) is routable between the ITS core network and Flint.
- Two blocks (10.215.0.0/16 and 10.216.0.0/16) are routable between Dearborn and Flint.
Note: Units must request private IP address space from their campus core network provider to ensure addressing conflicts do not exist.
10.0.0.0/8 Assignments
| Core Network | Prefix | First Address | Last Address | Announcement |
|---|---|---|---|---|
| Any | 10.0.0.0/9 | 10.0.0.0 | 10.127.255.255 | Not announced (There are exceptions. See 10.0.0.0/8 Exceptions table below) |
| Michigan Medicine | 10.128.0.0/11 | 10.128.0.0 | 10.159.255.255 | Announced by Michigan Medicine |
| UMnet | 10.160.0.0/11 | 10.160.0.0 | 10.191.255.255 | Announced by UMnet |
| Shared | 10.192.0.0/11 | 10.192.0.0 | 10.223.255.255 | Sub-prefixes announced by mutual agreement (See 10.0.0.0/8 Prefixes Announced by Mutual Agreement table below) |
| UMnet | 10.224.0.0/11 | 10.224.0.0 | 10.255.255.255 | Announced by UMnet (See 10.255.0.0/16 special case in 10.0.0.0/8 Exceptions table below) |
10.0.0.0/8 Exceptions
| Prefix | Announced by | Comments |
|---|---|---|
| 10.75.144.0/20 | UMnet | Mirror of 207.75.144.0/20 |
| 10.108.8.0/21 | UMnet | Mirror of 198.108.8.0/21 |
| 10.111.0.0/16 | UMnet Engineering Lab | Mirror of 198.111.0.0/16 |
| 10.255.0.0/16 | Not Routed |
LAN-Local. No central DNS or DHCP services to LAN-Local addresses. |
10.0.0.0/8 Prefixes Announced by Mutual Agreement
| Prefix | Announced by | Comments |
|---|---|---|
| 10.194.0.0/16 | UMnet | Mirror of 67.194.0.0/16 |
| 10.196.0.0/14 | UMnet |
Virtual Data Center service in the Amazon cloud (AWS). Approved 2017-11-21. |
| 10.200.0.0/16 | U-M Dearborn | Approved 2024-10-01. |
| 10.211.0.0/16 | UMnet | Mirror of 141.211.0.0/16 |
| 10.212.0.0/16 | UMnet | Mirror of 141.212.0.0/16 |
| 10.213.0.0/16 | UMnet | Mirror of 141.213.0.0/17 |
| 10.214.0.0/16 | Michigan Medicine | Mirror of 141.214.0.0/16 |
| 10.215.0.0/16 | U-M Dearborn | Mirror of 141.215.0.0/16 |
| 10.216.0.0/16 | U-M Flint | Mirror of 141.216.0.0/16 |
| 10.223.0.0/16 | UMnet | Special cloud connections. Approved 2020-08-04. |
Note: The mirrored IP prefixes above are reserved for use on the networks where mirrored public prefixes are used. Units needing private IP space can generally assume that these prefixes will be available for intra-campus use. Contact [email protected] to activate these private prefixes.
172.16.0.0/12 Assignments
| Backbone | Prefix | First Address | Last Address | Announcement | Comments |
|---|---|---|---|---|---|
| Michigan Medicine | 172.16.0.0/16 | 172.16.0.0 | 172.16.255.255 | Announced by Michigan Medicine | |
| Michigan Medicine | 172.17.0.0/16 | 172.17.0.0 | 172.17.255.255 | Announced by Michigan Medicine | |
| None | 172.18.0.0/16 | 172.18.0.0 | 172.18.255.255 | Not announced | Reserved for future use |
| None | 172.19.0.0/16 | 172.19.0.0 | 172.19.255.255 | Not announced | Reserved for future use |
| Any | 172.20.0.0/16 | 172.20.0.0 | 172.20.255.255 | Not announced | |
| UMnet | 172.21.0.0/16 | 172.21.0.0 | 172.21.255.255 | Announced by UMnet | |
| Any | 172.22.0.0/16 | 172.22.0.0 | 172.22.255.255 | Not announced | |
| UMnet | 172.23.0.0/16 | 172.23.0.0 | 172.23.255.255 | Announced by UMnet | |
| Any | 172.24.0.0/16 | 172.24.0.0 | 172.24.255.255 | Not announced | |
| Any | 172.25.0.0/16 | 172.25.0.0 | 172.25.255.255 | Not announced | |
| Any | 172.26.0.0/16 | 172.26.0.0 | 172.26.255.255 | Not announced | |
| None | 172.27.0.0/16 | 172.27.0.0 | 172.27.255.255 | Not announced | Reserved for future use |
| UMnet | 172.28.0.0/16 | 172.28.0.0 | 172.28.255.255 | Announced by UMnet | |
| UMnet | 172.29.0.0/16 | 172.29.0.0 | 172.29.255.255 | Announced by UMnet | |
| Michigan Medicine | 172.30.0.0/16 | 172.30.0.0 | 172.30.255.255 | Announced by Michigan Medicine | |
| Dearborn | 172.31.0.0/17 | 172.31.0.0 | 172.31.127.255 | Announced by U-M Dearborn | |
| Flint | 172.31.128.0/17 | 172.31.128.0 | 172.31.255.255 | Announced by U-M Flint |
192.168.0.0/16 Assignments
| Core Network | Prefix | First Address | Last Address | Announcement |
|---|---|---|---|---|
| Shared | 192.168.0.0/18 | 192.168.0.0 | 192.168.63.255 | Sub-prefixes announced by mutual agreement (See 192.168.0.0/16 Prefixes Announced by Mutual Agreement table below) |
| Any | 192.168.64.0/18 | 192.168.64.0 | 192.168.127.255 | Not announced |
| Any | 192.168.128.0/17 | 192.168.128.0 | 192.168.255.255 |
Not announced. Reserved for LAN-local use. May be used freely on any LAN. Will never be routed across the core network. LAN-Local addresses have no central DNS or DHCP services. |
192.168.0.0/16 Prefixes Announced by Mutual Agreement
| Prefix | Announced by | Comments |
|---|---|---|
| none |