DNS Nameservers

It’s common folklore in the Domain Name System that a delegated domain name must be served by 2 or more nameservers. The logic for this is based in a desire for service resilience. If one server is unreachable then hopefully the other is not, and recursive resolvers when presented with…


Post-Quantum Cryptography

It may be useful to start this article by defining what I am talking about. No, “Post-Quantum Cryptography” is not about using the next generation of computer processors that may come after quantum computing, whatever that may be, to perform cryptography. It’s not even about “Quantum Cryptography”, which is all…


DNS OARC 43

The DNS Operations, Analysis, and Research Center (DNS-OARC) brings together DNS service operators, DNS software implementors, and researchers together to share concerns, information and learn together about the operation and evolution of the DNS. They meet between two to three times a year in a workshops format. The most recent…


Ethernet at NANOG 92

Ethernet has been the mainstay of much of the networking environment for almost 50 years now, but that doesn’t mean that it’s remained unchanged over that period. The evolution of this technology has featured continual increases in the scale of Ethernet networks, increasing in capacity, reach and connections. I’d like…


The IPv6 Transition

I wrote an article in May 2022, asking “Are we there yet?” about the transition to IPv6. At the time I concluded the article on an optimistic note, observing that we may not be ending the transition just yet, but we are closing in. I thought at the time that…


The Size of Packets

We’ve now been running packet-switched networks for many decades, and these days it’s packets and not virtual circuits lie behind most of the world’s digital communications service. But some very fundamental questions remain unanswered in this packet-switched world. Perhaps the most basic question is: “How big should a packet be?”…


The Evolution of PON

AUSNOG, the Australian Network Operator’s Group meetings, have always managed to assemble a program that represents a fascinating window into the diversity of activities in the Australian communications environment. This year the program included the use of femtocells raised to a useful height by tethered drones to provide fast response…


Looking for 240/4 Addresses

If you look through the IANA’s IPv4 address registry you will find a set of reservations which collectively are encompasses by the address prefix 240/4, and are annotated in the registry for “Future Use.” These entries reference RFC 1112 section 4, which states: “Class E IP addresses, i.e., those with…


Bytes from IETF 120 – A Few Routing Topics

There was, as usual, a lot of work in the area of Inter-Domain Routing at IETF 120. There is the long-standing Inter-Domain Routing (IDR) working group, looking at the specification o0f the BGP protocol and its refinements for particular deployment scenarios such as 5G networks, or certain service quality assurance,…


Bytes from IETF 120 – Deep Space Networking

The IEPG meets each Sunday at the start of the IETF week. The intended theme of these meetings is essentially one of operational relevance in some form or fashion – although the chairs will readily admit that they will run with an agenda of whatever is on offer at the…