37.186.83.in-addr.arpa is a domain controlled by two nameservers at dns.swip.net. They are on the same IP network. op.se, mm.se, do.se, skk.se, jgv.se and at least 100 other hosts share nameservers with this domain. 186.83.in-addr.arpa is a domain controlled by four nameservers. All of them are on different IP networks.