RFC1918 and RFC 2365 describe sets of network ranges reserved for so-called "private use". These have a number of existing uses within Oxford, and their importance is increasing as a means of alleviating pressure on our public IPv4 address allocation. ITSS should consider the use of RFC1918 addresses for devices which have no need to contact the Internet or be accessible to other systems in Oxford, such as printers and network switches.
The available RFC1918 subnets for use within the college/Department internal networks are listed below. By avoiding use of This will eventually allow us to allocate and hence route some RFC1918 addresses within the Odin network, giving greater scope for (re-)using the remaining limited public IP address space.
RFC1918 range usage
While you can technically use any RFC1918 networks you like within your own local network scope (this is how RFC1918 was designated), you may find it helpful to avoid certain ranges in order to avoid complications for staff and students, benefit from central services or co-exist amicably with other providers.
RFC1918 Range |
Subnet |
Description |
10.0.0.0 |
10.0.0.0/9 |
Avoid - may be used in the University's backbone global routing table or be assigned records in the DNS, as per the IPv4 Address Allocation Policy |
10.0.0.0 |
10.128.0.0/9 |
Free to use |
172.16.0.0 |
172.16.0.0/12 |
Avoid - this netblock is used by central networking infrastructure and may feature in the DNS, as per the IPv4 Address Allocation Policy |
192.168.0.0 |
192.168.0.0/16 |
Free to use |