53.115.131.in-addr.arpa is a domain controlled by two nameservers at telia.se. They are on the same IP network. di.se, sdc.se, dof.se, ditv.se, diego.se and at least 62 other hosts share nameservers with this domain. 115.131.in-addr.arpa is delegated to three nameservers, however one extra nameserver is listed in the zone. Two of them are on the same IP network.