How the pfBlockerNG Tracker ID number is created :
Each Firewall rule for pfBlockerNG is assigned a unique Tracker Number.
This Number can be used in a Remote syslog so that Events can be tracked by this unique Tracker Number.Tracker Number function is here:
https://github.com/pfsense/FreeBSD-ports/blob/devel/net/pfSense-pkg-pfBlockerNG/files/usr/local/pkg/pfblockerng/pfblockerng.inc#L2036
Basically it takes the Alias Name, various Interface Information and converts this to a unique tracker number…
All pfBlockerNG Tracker Numbers start with "177"