IP address allocations

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Here is the list of IPv4 addresses owned by the University:

Network Mask Mask in bits Description /16 "Old" /16 /16 "New" /16 /23 192.76.6-7 /21 192.76.8-15 /20 192.76.16-31 /22 192.76.32-35


Here is the list of IPv6 addresses owned by the University:

Prefix Prefix length Description
2001:630:440:: 44 Oxford IPv6 range (old), deprecated and will be removed from allocation 31/12/2024
2a0a:200:: 29 Oxford IPv6 range (new)


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 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 Free to use Avoid - this netblock is used by central networking infrastructure and may feature in the DNS, as per the IPv4 Address Allocation Policy Free to use


Some services provided by IT Services 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 owl.oxuni.org.uk
eduroam eduroam.oxuni.org.uk

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 Partner Organisations. 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.

IT Services 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.

If you need to add, change or remove IP subnet allocations then please see our guide How to request / change / release subnet allocation.

Allocations from within the University's IP address ranges, together with private address usage on the University backbone, can be viewed in Hydra:


If you are ITSS but do not have access to Hydra then you can access a nightly snapshot of subnet allocations instead:


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