The University's reserves of IPv4 addresses are low. When this policy was originally implemented it was calculated that at the then rate of assignment, approximately two years' supply remained. The Internet Exhaustion Group (IEG), now a sub-group of the Network Advisory Group, was setup to manage the remaining address space and has stabilised the depletion rate. However, as IPv6 implementation has now been delayed, IEG been tasked (NAG 98, Nov'2019) to manage the reserves for another 10 years.
- IPv6 is not the only answer - systems will require access to IPv4-only services for the foreseeable future
- There is almost no possibility of acquiring additional IPv4 address space, certainly not without paying
- We are unlikely to be able to recover significant amounts of address space from existing allocations - most cannot easily be relinquished
- We cannot afford to run out entirely and so reserves must be retained for future expansion of the University
- Future IPv4 allocations will be limited to a maximum of 256 addresses (ie a /24 subnet). An extremely strong justification must be made to the IEG for any exception to this
- The future is considerably more NAT. However this is implemented, it will bring its own challenges and incur significant (direct and indirect) costs for the University