NetLdn #73 is today

[Ben Cartwright-Cox]

Reminder to everyone that NetLdn is today rather than tomorrow for this month

== NetLdn 73 ==

NetLdn 73 will be on ***Wednesday*** 10th of June 2026, with arrival from
1830hrs and talks starting promptly at 1900hrs at Finch’s in Finsbury Square:

(Due to an unfortunate pub booking error, we are running this one on a
wednesday this time, normal thursday meetings will resume shortly)

If you can make it, please do. We've been lucky enough to not have a
min bar spend, but we do need to prove to our new hosts that we're
worth a long-term standing booking!

Henry’s Den, Downstairs @ Finch’s
12a Finsbury Square, London EC2A 1AN

https://www.finchspub.co.uk/ |
https://maps.app.goo.gl/GkfULQMwj832Q3sh8

== Talks ==

Talk 1: It’s Always DNS

David Groves (Nominet)

How swapping my home router broke my home automation and my wife’s
investment app.

--

Talk 2: Persistent Unknown Unicast

James Rice (Jump Networks Ltd)

Unknown unicast on shared peering LANs is widely assumed to be
transient. This case study presents the opposite: a self-perpetuating
mechanism via RFC 4861 §7.3.1 forward-progress confirmation, where a
single MAC change can leave a stale neighbour entry REACHABLE
indefinitely while customer traffic — HTTPS SNI, signalling,
residential 999 calls — is flooded to hundreds of member ports. A
reproducible demonstration was published in November 2024. The talk
presents the mechanism at the kernel and protocol level, a five-year
timeline of reports and partial remediations at one IXP, the
categories of disclosure and safety-of-life exposure at stake, and
operational lessons for IXP operators and members. It closes on the
speaker’s open self-examination: did I do enough on behalf of my
customers?


________________________________


== Participating and Contact ==

If you are attending any NetLdn event we expect that you have read and
agree to the participation policy on the NetLdn website
(https://netldn.uk/respect-policy/), we want to keep NetLdn open,
friendly, and safe for everyone. This also applies to all NetLdn
interactions, for example the mailing list, and Slack space, not just
the meetings.

* If you're attending NetLdn please note that the venue is a pub which
serves alcohol. There is no expectation that you must drink alcohol,
non-alcoholic drinks are also available. If you're under 18 please let
us know, we will need to inform the landlord. If you're crazy enough
to drive in London, please drink responsibly.

If you want to submit a talk for a future event, any area of
networking and any skill level is welcome. Please respond to our call
for presentations via the NetLdn website: https://netldn.uk/cfp/

If you want to contact the NetLdn team about any issues, concerns or
queries please do so via:

Email: he...@neldn.uk
Bluesky: https://bsky.app/profile/netldn.bsky.social
Slack: netldn.slack.com

Many thanks and we hope to see you all soon,
The NetLdn Team.