Ipv6

Or, ‘NATs continue to be evil’, or ‘the more expensive the hotel, the stupider the captive portal system’. TL;DR: When not at home, you realise how broken the internet access usually is. Problem 1: Not enough addresses Originally IPv4 addressing was designed with 2^32 addresses (some of which are reserved) which was supposed to be enough (and perhaps in the 70s and early 80s, it was good assumption). The lack of addresses was seen as a problem and IETF designed a solution for it in the 90s - IPv6 (c.f. RFC 2460: Internet Protocol, Version 6 (IPv6) Specification). Unfortunately due to various technical reason its availability is still quite low - according to Google it is currently less than half the hosts even now ( see Google IPv6 access statistics). ...

Two weeks ago I experienced IPv6-less life for a week thanks to my ISP, but my ISP provided me this week an experience of what IPv6-only life looks like. The start of the IPv6-only experience (bit before 6am) I wake up usually crazily early in the morning (by nerd standards, at any rate), if it is light out there. And in Finland, at summer, it gets light quite early so I must have woken up a bit before 6 am or so. I usually start working (or tinkering with some hobby project) even before breakfast, so I hopped on my computer. ...

Based on my metrics and logs, around 1 am on the 15th of May, 2023, my (cable modem-based) internet provider just stopped providing IPv6 addressing to me. According to the logs, the first indication of trouble was 03:34 or so, when odhcpd started logging messages about no default route being present (IPv6 one) and my home network hosts lost IPv6 connectivity subsequently. Then I looked at stored netflows: mstenber@fw ~>nfdump -R /flows/2024/05/ -t 2024/05/15.00:00:00 ipv6 2>&1 | egrep -v '(fe80|fd42|ff02):' Date first seen Duration Proto Src IP Addr:Port Dst IP Addr:Port Packets Bytes Flows ... 2024-05-15 01:20:45.525 00:00:00.000 TCP 2001:14..79:115c.60513 -> 2a01:b7..01::2:4.443 1 84 1 The last failed attempt to even use IPv6 was apparently around 1:20. So it most likely broke two, three hours earlier than what was shown in the logs, and just the default route lifetime expired at the point when odhcpd started being unhappy. ...