ns3.etecsa.net has one IP number , which also has a corresponding reverse pointer. ce.cu, co.cu, ipf.cu, iga.cu, one.cu and at least 100 other hosts use this as a nameserver. etecsa.net is a domain controlled by four nameservers at etecsa.net themselves. All of them are on the same IP network. Incoming mail for etecsa.net is handled by one mailserver also at etecsa.net. ns3.etecsa.net is hosted on a server in Cuba.