15.175.129.in-addr.arpa is a domain controlled by two nameservers on different IP networks. lri.fr, ens.fr, ecp.fr, pcri.fr, cnam.fr and at least 56 other hosts share nameservers with this domain. 175.129.in-addr.arpa is delegated to two nameservers, however both delegated nameservers are missing in the zone. All nameservers are at dns.u-psud.fr. They are on the same IP network.