AS7973 MAYO

MAYO is the Autonomous System of the **Mayo Foundation for Medical Education and

Research — the legal entity behind Mayo Clinic**, the nonprofit academic

medical center headquartered in Rochester, Minnesota.

What it's used for

• Mayo Clinic's enterprise network: hospitals, clinics, research institutes and the Mayo Clinic College of Medicine and Science, across its Minnesota, Arizona and Florida campuses and its regional health system.
• Clinical and corporate IT. rDNS across the space is uniformly mayo.edu — router-128.mayo.edu and router2-128.mayo.edu for edge routing, plus internal-looking application and management hosts.

Notable

• Despite the .edu domain and the "Medical Education and Research" name, this behaves as a large institutional enterprise network, not a campus ISP and not a public research network. There are no subscriber pools of any kind.
• It announces 129.176.0.0/16, a legacy Class B, deaggregated into /19s — roughly 65,000 addresses. Traffic from this AS is clinicians, researchers and staff on Mayo's own estate, and its public-facing patient-portal and web presence.
• Healthcare networks of this size are heavily segmented and egress through enterprise proxies, so outbound addresses are shared by very large numbers of users.

Interesting

• Mayo has held the AS number since 1997, and its .edu domain reflects a genuine degree-granting medical school rather than a marketing choice.