
According to RFC4291[1], 2001:db8:: is the anycast address for the prefix and will be answered by all routers responsible for this prefix. This means that before the iputils bump, the ping from client to isp was answered by the router and not by the ISP machine. Switching away from the anycast address fixes this issue. Credits for finding this go to @primeos. [1]: https://tools.ietf.org/html/rfc4291#section-2.6.1 Fixes #96188
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