The IP address ranges allocated to the university consist primarily of two main networks, namely 163.1.0.0/16 and 129.67.0.0/16 (historically, these were "class B" networks). Additionally the university has been assigned several /24 networks starting 192.76 (originally "class C" networks). These are used by OUCS for special purposes, and by one or two departments for historical reasons.
1. Other allocations
The University also uses further IP address space which is specifically assigned for use by visitors to the University. This should not be regarded as University address space when setting up IP-based access controls.
Additionally the university provides connectivity for several associated institutions as JANET sponsored connections. These institutions will have their own IP address space which is routed by the University but should not be regarded as being part of the University.
2. Private address space
The University also makes some use of private address space, RFC 1918 addresses for unicast and RFC 2365 addresses for multicast. It is recommended that you avoid making private address space assignments which conflict with the University allocations to avoid possible future problems.
3. Location Independent Networks
Some services provided by OUCS are available in many buildings throughout the collegiate University. These networks use dynamic IP allocation (DHCP) and to allow a large number of users to connect the clients receive so-called Private (RFC1918) addresses which are translated into University owned IPs.
The following table lists private and public allocations in use by these Location Independent Networks (LIN). Note that for efficiency the IP Subnet configured via DHCP on a client on a LIN service may be smaller than the block shown here.
| LIN Service | Private IP Range | Public IP Range | DNS Domain |
| OWL | 10.0.0.0/12 | 192.76.7.128/26 | visitor-network.oxuni.org.uk |
| Eduroam | 10.16.0.0/12 | 192.76.7.192/26 | eduroam.oxuni.org.uk |
| OWL-VPN (legacy service) | 172.17.48.0/20 | Not Applicable | Not Applicable |
4. IPv6
The University's IPv6 address allocation is 2001:630:440::/44. See the further IPv6 information for deployment progress and details.
5. Subnet assignments
OUCS will assign subnets to college and departments based upon their current and predicted needs. Subnets will typically range from a /28 (13 usable addresses) up to a /22 (1021 usable addresses), with /30 networks used for point-to-point links between the backbone and routing firewalls. Existing assignments may be enlarged; see Subnet change procedure for further details (access is restricted to University hosts).
6. List of network allocations
Allocations from within the University's IP address ranges, together with private address usage on the University backbone are available for viewing (Oxford only).