[amsat-bb] ISS/NO-84 APRS filter to avoid local uplink dupes ?

[PA3GUO]

APRS question:

I am using AGWUIDigi to Igate the 145.825 data from ISS, NO-84, etc.

How do I avoid that when a local HAM uplinks to ISS, I hear his
uplink, I Igate his uplink, and then when ISS digipeats, that is seen
as a dupe ?
Result would be that that local HAM would never show up anywhere as
heard via ISS or NO-84, as I would have Igated his uplink 2 seconds
prior to the digipeat.

Setting the APRS server logon filter to exclude his CALLSIGN, would
that block just incoming or also outgoing (RF to Internet) packets ?
If so, I could use such a filter: -b/CALLSIGN

Would this be the way to solve this ?

Henk, PA3GUO