We pick j.root-servers.net, one of the 13 root servers (1), and ask it about wardcomsystems.com and learn that com is delegated to 13 name servers (2), so we ask a.gtld-servers.net where we learn that wardcomsystems.com is delegated to two name servers, including yns2.yahoo.com (3), so we ask that one and get the following answer:
Wardcomsystems.com is a domain controlled by two domain name servers at yahoo.com. Both are on different IP networks. Incoming mail for wardcomsystems.com is handled by four mail servers also at yahoo.com having a total of four IP numbers. There are two duplicated IP numbers. All four of them are on different IP networks. Wardcomsystems.com has two IP numbers (98.139.135.22, 98.139.135.21). Both are on the same IP network.
The two IPv4 numbers 98.139.135.21 and 98.139.135.22 together
There are several thousand of domains that use IPv4 group 1.
Three quarter of those use the two mail servers mx1 and mx5.biz.mail.yahoo.com together, hereafter referred to as "mail server group 1", (example: 8trackdoctor.com, mentaltainment.com and gtaleaf.com ). Worth noting is that one percent of the domains that use mail server group 1 use IPv4 group 1.