AS11493 HILLSBOROUGH-COUNTY-SHERIFFS-OFFICE

HILLSBOROUGH-COUNTY-SHERIFFS-OFFICE is exactly what the handle says: the network of the Sheriff's Office for Hillsborough County, Florida — the county that contains Tampa, and one of the largest sheriff's agencies in the state. RIS sees 3 IPv4 prefixes totalling 1,280 addresses, no IPv6, and 3 observed BGP neighbours.

What it's used for

Local-government law-enforcement IT. The announced space is 198.199.20.0/23, 198.199.24.0/23 and 198.135.199.0/24, and all three are registered to the Sheriff's Office itself under the HCSONET netblock handles, so this is self-held space rather than a carrier assignment. The reverse DNS confirms the use: sampled addresses answer as mail.hcso.tampa.fl.us and mail2.teamhcso.com — the agency's own mail infrastructure on its own .fl.us government domain, plus its public-facing teamhcso.com brand. A network of this size with three upstreams and its own AS number is an organisation that wants multi-homed resilience for services that cannot go dark, which is the normal posture for public-safety and dispatch-adjacent systems.

Notable

This is one of the more distinctly local government networks in the low-AS range: not a federal agency or a state backbone, but a single county sheriff's department that acquired its own autonomous system. Public-safety agencies of this size usually sit behind a county or municipal network; running independent BGP with its own PI space is a deliberate choice about who controls the routing.