Summary
21.71.194.in-addr.arpa is delegated to three nameservers, however one delegated nameserver is missing in the zone. Two of them are on the same IP network.
lfv.se,
fov.se,
fcc.se,
ssab.se,
rcb2.se and at least 81 other hosts share nameservers with this domain.
71.194.in-addr.arpa is a domain controlled by five nameservers. All of them are on different IP networks.