ns2.cisco.com has one IP number , which also has a corresponding reverse pointer. mp.net, ieng.net, tidal.net, okena.net, e-life.tv and at least 100 other hosts use this as a nameserver. cisco.com is a domain controlled by two nameservers at cisco.com themselves. They are on different IP networks. Incoming mail for cisco.com is handled by nine mailservers also at cisco.com. Some of them are on the same IP network. cisco.com has one IP number. ns2.cisco.com is hosted on a server in United States.