Raw Sockets in IPv6

Among many other functions performed by a computer’s operating system, there is typically an interface to a shared local network protocol engine. This means that applications that run within the operating system’s environment don’t need to implement their own network protocol engine, as they can make use of a shared…


IPv6 Fragmentation Extension Headers, Part 2

The first part of this article looked at what happens when an authoritative DNS server delivers fragmented UDP responses to DNS resolvers using IPv6. The result from this experiment was that: Some 37% of endpoints used IPv6-capable DNS resolvers that were incapable of receiving a fragmented IPv6 response over UDP.…


IPv6, Large UDP Packets and the DNS

The IPv6 protocol introduced very few changes to its IPv4 predecessor. The major change was of course the expansion of the size of the IP source and destination address fields in the packet header from 32-bits to 128-bits. There were, however, some other changes that apparently were intended to subtly…


RIPE 74

RIPE 74 was held in May in Budapest, and as usual it was a meeting that mixed a diverse set of conversations and topics into a very busy week. Here are my impressions of the meeting drawn from a number of presentations that I found to be of personal interest.…


IETF 98 Report

The IETF meetings are relatively packed events lasting over a week, and it’s just not possible to attend every session. Inevitably each attendee follows their own interests and participates in Working Group sessions that are relevant and interesting to them. I do much the same when I attend IETF meetings.…


Scoring the DNS Root Server System, Pt 2 – A Sixth Star?

In November I wrote about some simple tests that I had undertaken on the DNS Root nameservers. The tests looked at the way the various servers responded when they presented a UDP DNS response that was larger than 1,280 octets. I awarded each of the name servers up to five…


IPv6 and the DNS

The exhortations about the Internet’s prolonged transition to version 6 of the Internet Protocol continue, although after some two decades the intensity of the rhetoric has faded and, possibly surprisingly, it has been replaced by action in some notable parts of the Internet. But how do we know there is…


Labs retires the old ipv6-measurement graphs

As the stats.labs.apnic.net/ipv6 code has reached a stable service, we’ve decided to retire the old labs.apnic.net/ipv6-measurement/ tree of graphs. For people with saved URLs, it should redirect to the new service, and should map an ASN or Economy to the right dataset. For people who are farming the site for…


Binding to an IPv6 Subnet

by Joao Luis Silva Damas and Geoff Huston    In the original framework of the IP architecture, hosts had network interfaces, and network interfaces had single IP addresses. The list of active network interfaces, and the manner in which they acquire IP addresses, either by a static configuration or by…


IPv6 Performance – Revisited

Every so often I hear the claim that some service or other has deliberately chosen not to support IPv6, and the reason cited is not because of some technical issue, or some cost or business issue, but simply because the service operator is of the view that IPv6 offers an…