AS10359 — EPICSYS

AS10359 announces 1 IPv4 prefixes covering 1,024 addresses and 1 IPv6 prefixes.

About this network

EPICSYS is Epic Systems Corporation, the privately-held healthcare software company in Verona, Wisconsin whose electronic health record runs a large share of US hospital systems. This is Epic's own corporate network, not a product platform.

What it's used for

• Corporate connectivity for Epic's Verona campus: staff internet egress, the company's public-facing services, and border infrastructure.
• The sampled reverse DNS says exactly this. ub3-1-border-2.epic.com is a border router, and pat-verona-5.epic.com names a PAT (port-address-translation) address at the Verona campus — that is outbound NAT for corporate users, which is a workplace network's most characteristic artefact.

Notable

• Enterprise, decisively. RIS sees a single IPv4 prefix (199.204.56.0/22, 1,024 addresses) and one IPv6 /48 (2620:72::/48), announced across 3 observed BGP neighbours. Three upstreams for one /22 is a company that wants redundant internet for its own site and nothing more. There is no customer cone, no hosting fragmentation, and no subscriber pool.
• The tiny address footprint is itself informative: Epic's scale lives inside its customers' hospital data centres and in its own private connectivity, not in publicly-routed space.

Interesting

• A /22 and a /48 is a modest routing presence for a company of Epic's size and criticality — a good reminder that announced address volume measures a network's public surface, not the organisation behind it.

This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy.

Announced prefixes

• 199.204.56.0/22
• 2620:72::/48

Upstream networks

• AS4181 TDS TELECOM
• AS40264 Charter Communications LLC
• AS11796 Airstream Communications, LLC

Adjacent networks

• AS4181 TDS TELECOM
• AS40264 Charter Communications LLC
• AS11796 Airstream Communications, LLC