sprint.se use this as a nameserver. brv.se, camu.dk, buur.dk, aeit.se, cist.dk and at least 77 other hosts use this as a mailserver. b-one.net is a domain controlled by two nameservers at b-one-dns.net. They are on the same IP network. Incoming mail for b-one.net is handled by two mailservers at one.com. They are on the same IP network. b-one.net has one IP number.