slave1.ccoo.es has one IP number , but the reverse is artemis.ttd.net. ns4.sergas.es, artemis.ttd.es and artemis.ttd.net point to the same IP. ccoo.es use this as a nameserver. ccoo.es is delegated to three nameservers, however two delegated nameservers are missing in the zone and two other nameservers are listed instead. There are two duplicated IP numbers. All of them are on the same IP network. Incoming mail for ccoo.es is handled by two mailservers on different IP networks. ccoo.es has one IP number. slave1.ccoo.es is hosted on a server in Spain.