RIPE NCC has Approximately Four Million IPv4 Addresses Before Reaching Last /8.

RIPE NCC has just announced that it now has only 4 million IPv4 addresses left to allocate, or .1% of the total IPv4 space. In addition it is recycling and reissuing returned IPv4 address space however this is expected to have only a small impact in extending the period before IPv4 is exhausted - probably end 2012 early 2013. Once the final /8 (16 million addresses) is reached all existing LIRs will be given a /22 (1000 addresses) and there will be no more new IPv4 addresses left in the Europe/Middle East region. HIT Rail, as an LIR, has 2x /21 and will be allocated a further /22 in IPv4 space making 5120 IPv4 addresses or 20 x 256 addresses enough for over 600 customers with /29 (8 addresses). We currently have allocated addresses in 5 of the 256 addresses ranges 93.94.200-204 inclusive. So we do not anticipate any urgent need to migrate to IPv6 until requested by the GPH based on their wish to migrate their networks. HIT Rail have already been allocated an IPv6 first allocation /32. IPv6 works differently to IPv4 and the table below gives an indication of the size and how it would be used. This would allow HIT Rail to allocate a /56 to 16 million customers. Any questions please contact

IPv6 Relative Network Sizes


1 IPv6 address

A network interface


1 IPv6 subnet

18,446,744,073,709,551,616 IPv6 addresses


256 LAN segments

Popular prefix size for one smaller subscriber site


65,536 LAN segments

Popular prefix size for one large subscriber site


65,536 /48 subscriber sites

Minimum IPv6 allocation

6 Sep 2012