Anything to be aware of on layer 2 when activating dual stack? IPv4 and IPv6 should after all peacefully and safely coexist on the same network as each version has a specific layer 2 ethernet type, 0x0800 for IPv4 while IPv6 responds to 0x86dd. The value of this field tells the node which layer 3 protocol follows in the ethernet frame. Is this new? Not really, this was defined in RFC 2464 in December 1998, more than a decade ago. The IEEE Ethernet Field Registrar issues and maintains the list of allocated Ethernet types. And 0x0800, the IPv4 ethernet type, result of the venerable RFC894, will be a quarter century old next month! This RFC defines a standard protocol for the ARPA—internet community (sic).

Remarkable how Ethernet has evolved and been widely adopted over this period extending its reach from LAN to MAN to WAN and from 10meg to 10gigE. One has to credit the IEEE for quite an efficient job as a standards body.

Over in the IP world, this month of March will see IETF 74 meet in San Francisco and continue to ponder transitions, address translations, double translations, even carrier grade translations. In the meantime the IPv4 pool has shrivelled to 32 /8’s in IANA’s free pool and in Manila last week the policy session at the APNIC meeting further looked at ways to cut the remaining IPv4 address pool in ever smaller pieces and even allocating them for shorter time frames to somehow delay the inevitable. The Regional Internet Registries now even have a mechanism to equitably share recovered, reclaimed and returned pieces of IPv4 address property. APNIC has even adopted a proposition on how to parcel out crumbs of the very last /8 they will get allocated.

A modern day Géricault might start painting the “Radeau du IPv4”. I felt reassured however by the growing number of IPv6 address allocations by RIR’s to local registries and ISP’s as we saw in the NRO update [PPT]. Let’s just start using them a bit faster and pity the poor souls who will be left on the IPv4 raft.