2001:8d8:100f:f000::21b
Reverse address entry: b.1.2.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.f.f.0.0.1.8.d.8.0.1.0.0.2.ip6.arpa
2001:8d8:100f:f000::21b has no DNS entries .
Explore by label: b . 1 . 2 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . 0 . f . f . 0 . 0 . 1 . 8 . d . 8 . 0 . 1 . 0 . 0 . 2 . ip6 . arpa
DNS Records 
PTR2001-08d8-100f-f000-0000-0000-0000-021b.elastic-ssl.ui-r.com- Records pointing here:
AAAAgb.holzkunst-schad.de
Updating...
Whois for 2001:8d8:100f:f000::21b
This top-level domain has no publically available whois server. Try going to www.nic.arpa.
Ping
Updating...
Search 2001:8d8:100f:f000::21b
HTTP Port 80 Reply
_