TCP MSS Values

At the recent IEPG meeting in Montreal in July 2019 Joel Jaeggli of Fastly talked on the topic of the settings of the TCP Maximum Segment Size (MSS) field in TCP implementations. There has been a recent vulnerability published (described in CVE-2019-11477, 11478 and 11479) relating to the Linux TCP…


No So Private Thoughts at IETF 105

At IETF 105, held in Montreal at the end of July, the Technical Plenary part of the meeting had two speakers on the topic of privacy in today’s Internet, Associate Professor Arvind Narayanan of Princeton University [1] and Professor Steven Bellovin of Colombia University [2]. They were both quite disturbing…


Looking for What’s Not There

DNSSEC is often viewed as a solution looking for a problem. It seems only logical that there is some intrinsic value in being able to explicitly verify the veracity and currency of responses received from DNS queries, yet fleshing this proposition out with practical examples has proved challenging. The relatively…


Network Protocols and their Use

In June I participated in a workshop, organized by the Internet Architecture Board, on the topic of protocol design and effect, looking at the differences between initial design expectations and deployment realities. These are my impressions of the discussions that took place at this workshop. 1 – Case Studies In…


Happy Birthday BGP

The first RFC describing BGP, RFC 1105, was published in June 1989, thirty years ago. By any metric that makes BGP a venerable protocol in the internet context and considering that it holds the Internet together it’s still a central piece of the Internet’s infrastructure. How has this critically important…


Report: DNS OARC 30 Meeting

DNS OARC held its 30th meeting in Bangkok on the 12th and 13th May. Here’s what attracted my interest from two full days of DNS presentations and conversations, together with a summary of the other material that was presented at this workshop. Some Bad News for DANE (and DNSSEC) For…


Report: ICANN DNS Symposium

By any metric, the queries and responses that take place in the DNS are highly informative of the Internet and its use. But perhaps the level of interdependencies in this space is richer than we might think. When the IETF considered a proposal to explicitly withhold certain top level domains…


DNS Privacy at IETF 104

From time to time the IETF seriously grapples with its role with respect to technology relating to users’ privacy. Should the IETF publish standard specifications of technologies that facilitate third party eavesdropping on communications or should it refrain from working on such technologies? Should the IETF take further steps and…


Expanding the DNS Root: Hyperlocal vs NSEC Caching

I guess that for me April has been DNS month, as here is another article on the Domain Name System. This time I would like to look at the efforts to expand the root zone service by enabling recursive resolvers. The root zone of the DNS has been the focal…


More DOH

It seems that the previous article on DOH has generated some reaction, and also there is some further development that should be reported, all of which I’ll cover here. The previous article on the reactions to DOH at IETF 104 can be found at https://www.potaroo.net/ispcol/2019-04/angst.html. Default DOH First, with respect…