ns1.rogers.com has one IP number , which also has a corresponding reverse pointer. gatekeeper.microcell.ca point to the same IP. rnm.ca, tsc.ca, fido.ca, ckvu.ca, e-sc.com and at least 100 other hosts use this as a nameserver. root.ns1.rogers.com are subdomains to this hostname. rogers.com is a domain controlled by four nameservers. Some of them are on the same IP network. Incoming mail for rogers.com is handled by two mailservers having a total of three IP numbers. All of them are on different IP networks. rogers.com has one IP number. ns1.rogers.com is hosted on a server in Canada.