NOTIFY failed: connection reset

[kajt]

Hey everyone,

my knot is sending NOTIFY to the slave.dns.he.net which fail (connection reset):

Code Select Expand

NOTIFY, outgoing, 216.218.133.2@53: failed (connection reset)
NOTIFY, outgoing, 2001:470:600::2@53: failed (connection reset)

I have been using dns.he.net for quite some time now and I am pretty sure this worked at some time in the past.

[kajt]

NOTIFY should be sent to ns1.he.net (AXFR will the be pulled by slave.dns.he.net after a few seconds).
Is there a particular reason why ns1.he.net only resolves to IPv4?