$ dig +trace PTR 6.0.5.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.5.f.f.8.d.6.1.1.0.0.2.ip6.arpa.

; <<>> DiG 9.4.1-P1 <<>> +trace PTR 6.0.5.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.5.f.f.8.d.6.1.1.0.0.2.ip6.arpa.
;; global options:  printcmd
.                       508752  IN      NS      B.ROOT-SERVERS.NET.
.                       508752  IN      NS      C.ROOT-SERVERS.NET.
.                       508752  IN      NS      D.ROOT-SERVERS.NET.
.                       508752  IN      NS      E.ROOT-SERVERS.NET.
.                       508752  IN      NS      F.ROOT-SERVERS.NET.
.                       508752  IN      NS      G.ROOT-SERVERS.NET.
.                       508752  IN      NS      H.ROOT-SERVERS.NET.
.                       508752  IN      NS      I.ROOT-SERVERS.NET.
.                       508752  IN      NS      J.ROOT-SERVERS.NET.
.                       508752  IN      NS      K.ROOT-SERVERS.NET.
.                       508752  IN      NS      L.ROOT-SERVERS.NET.
.                       508752  IN      NS      M.ROOT-SERVERS.NET.
.                       508752  IN      NS      A.ROOT-SERVERS.NET.
;; Received 276 bytes from 10.0.0.1#53(10.0.0.1) in 2 ms

ip6.arpa.               172800  IN      NS      NS1.APNIC.NET.
ip6.arpa.               172800  IN      NS      TINNIE.ARIN.NET.
ip6.arpa.               172800  IN      NS      NS.ICANN.ORG.
ip6.arpa.               172800  IN      NS      NS-SEC.RIPE.NET.
ip6.arpa.               172800  IN      NS      NS.LACNIC.NET.
;; Received 219 bytes from 202.12.27.33#53(M.ROOT-SERVERS.NET) in 333 ms

8.d.6.1.1.0.0.2.ip6.arpa. 172800 IN     NS      ns4.q.p80.net.
8.d.6.1.1.0.0.2.ip6.arpa. 172800 IN     NS      ns1.q.port80.se.
8.d.6.1.1.0.0.2.ip6.arpa. 172800 IN     NS      ns2.q.port80.se.
8.d.6.1.1.0.0.2.ip6.arpa. 172800 IN     NS      ns3.q.p80.net.
;; Received 182 bytes from 200.160.0.7#53(NS.LACNIC.NET) in 312 ms

f.f.8.d.6.1.1.0.0.2.ip6.arpa. 60 IN     NS      ns1.sixxs.net.
f.f.8.d.6.1.1.0.0.2.ip6.arpa. 60 IN     NS      ns2.sixxs.net.
f.f.8.d.6.1.1.0.0.2.ip6.arpa. 60 IN     NS      ns3.sixxs.net.
;; Received 153 bytes from 82.96.2.250#53(ns2.q.port80.se) in 62 ms

2.5.f.f.8.d.6.1.1.0.0.2.ip6.arpa. 604800 IN NS  lillestrom.mlmm.no.
;; Received 122 bytes from 2001:7b8:3:1e:290:27ff:fe0c:5c5e#53(ns2.sixxs.net) in 110 ms

6.0.5.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.5.f.f.8.d.6.1.1.0.0.2.ip6.arpa. 604800 IN PTR irc.mlmm.no.
2.5.f.f.8.d.6.1.1.0.0.2.ip6.arpa. 604800 IN NS  dns.mlmm.no.
;; Received 133 bytes from 84.209.33.221#53(lillestrom.mlmm.no) in 23 ms