2017 Analysis of UK IPv4 and IPv6 address usage

15 December 2017

Ofcom requested RTFM llp to provide updated tables and charts for 2017 corresponding to the UK IP addressing analysis contained in the 2014 report RTFM produced for Ofcom.

Since the 2014 study, 777 UK-based LIRs have been formed and 155 have either merged or closed, a net gain of 622.

RIPE NCC has assigned approximately 1 million IPv4 addresses to its UK members since 2014. Three quarters of that address space was allocated to these new LIRs. The remaining addresses went to existing LIRs that have obtained their final single allocation of a /22 under current RIPE address policy.

Although there has been a small increase in IPv4 allocation and usage since the 2014 study, the trends are essentially flat. UK IPv4 allocations have increased from 69.5 million in 2014 to 70.5 million today, Reachability rates for UK IPv4 space has moved from 83% to 84% over the same period.

Apart from some acquisitions of space from legacy address holders, the major UK ISPs have not been particularly active in the IPv4 transfer market. Other than transfers from DWP’s 51/8 of 1M IPv4 addresses to Microsoft and another 0.5M to Sky, legacy space transfers involving UK organisations seem to be the result of corporate reorganisations and network rationalisation rather than a need to obtain more IPv4 addresses.

DWP has transferred over a third of its legacy space, 51/8. Approximately 2 million of those IPv4 addresses have gone to UK entities and 4 million to overseas organisations. BT, Plusnet and Sky have acquired some of this address space.

Uptake of IPv6 remains disappointing. Although the amount of allocated IPv6 space and the number of LIRs with IPv6 allocations has increased, the proportion of reachable IPv6 space held by UK-based LIRs has declined since 2014. This anomaly is explained by a very large IPv6 allocation to the Ministry of Defence in 2016 which has not yet become fully operational.

2017 Analysis of UK IPv4 and IPv6 address usage (PDF, 292.3 KB)