For a Let’s Encrypt cert i add a TXT record.
nsupdate -d <<EOF
server ns1.dynv6.com
zone bla.dynv6.net
update add_acme-challenge.bla.dynv6.net 120 TXT "ABCDEF1234567890"
key hmac-sha256:tsig-123.dynv6.com YourSHAREDsecret==
send
EOF
Works. Then I want to delete the same TXT record after I got the cert.
nsupdate -d <<EOF
server ns1.dynv6.com
zone bla.dynv6.net
update del _acme-challenge.bla.dynv6.net 0 TXT "ABCDEF1234567890"
key hmac-sha256:tsig-123.dynv6.com YourSHAREDsecret==
send
EOF
No error, but doesn’t work. TXT record is still there. Why? It is according to [RFC2136 2.5.4].