10. Feed Filter

Feed Filter 
 1. What Feed Filter does 
 Feed Filter filters messages before they are propagated to the rest of the system. 
 2. Main options 
 
 Enable Feed Filter enables/disables filtering globally. 
 Prohibit MLAT Positions strips MLAT lat/lon/track from BaseStation and drops MLAT Mode-S frames. 
 Block Unfilterable Feeds blocks passthrough/raw feeds that cannot be filtered per message. 
 
 3. ICAO filter mode 
 
 Blocklist ( ProhibitIcaos=true ): ICAOs in list/ranges are blocked. 
 Allowlist ( ProhibitIcaos=false ): only ICAOs in list/ranges are allowed. 
 Individual ICAO entries must be exactly 6 hex characters. 
 ICAO ranges are inclusive ( start and end included). 
 
 4. Apply behavior 
 
 no service restart required, 
 settings are hot-reloaded, 
 frontend/admin message indicates changes usually become visible within 2-5 minutes. 
 
 5. Safe rollout sequence 
 
 verify raw feed flow first (without filter), 
 enable filter with minimal scope, 
 validate map and list output after each step, 
 only then add additional ICAO rules/ranges.