31.76.64.in-addr.arpa is a domain controlled by five nameservers. All of them are on different IP networks. cph.com, quza.net, bmco.com, avid.com, gblx.net and at least 27 other hosts share nameservers with this domain. 136.31.76.64.in-addr.arpa are subdomains to this hostname. 76.64.in-addr.arpa is delegated to five nameservers, however all five delegated nameservers are missing in the zone. All of them are on different IP networks.