Summary

  • Rob Evans's RIPE proposal 2009-06 removed a promise to advertise one IPv6 prefix from the criteria for an initial allocation; LIR status and a two-year assignment plan remained.
  • The proposal was accepted on 15 September 2009 and implemented in October. Evans later coauthored Routing Working Group guidance for the more-specific routes that real networks sometimes need.

The application form that wanted a router

Imagine taking an IPv6 allocation form to an operator with two disconnected networks. The old text told an applicant to advertise its allocation as a single prefix if it would be used on the Internet. The boxes for being an LIR and planning assignments within two years made sense at a registry desk. The routing promise reached into another room. Rob Evans, then at JANET, put his name to RIPE 2009-06 in May 2009 to remove it.

The draft's side-by-side text makes the edit almost comically small: item two in section 5.1.1 disappears. The LIR requirement and two-year plan stay. A sentence tying minimum allocation size to prefix filtering also leaves section 4.3; the /32 minimum stays. The policy still describes aggregation as an address-management goal. Its routability section already says an allocation carries no guarantee of being globally routed. One deleted checklist item clarified who gets to decide what a router announces.

Evans's case came from operating practice. Networks with separate islands or traffic-engineering needs could have a legitimate reason to advertise more-specific prefixes. In the proposal's impact analysis, RIPE NCC modeled a possible increase of about 1,800 IPv6 table entries, using a then-observed IPv4 deaggregation factor of 3.4 and roughly 750 IPv6 allocations visible in routing tables. Those numbers were a forecast for the decision, not a tally of what later happened. The proposal was accepted on 15 September 2009; an 8 October implementation notice said RIPE NCC was ready to take requests under the revised policy.

The routing argument went to people whose business is routing. In 2011 Evans and Philip Smith published RIPE-532, recommending bounded use of more-specific IPv6 routes where networks are disconnected or traffic engineering calls for them. Evans's RIPE biography records a decade co-chairing the Routing Working Group. He had taken BGP out of the allocation form, then kept the hard discussion alive in the room that runs BGP.