The GBUdbIgnoreList.txt file is a safety net that ensures IPs that are part of your infrastructure (such as eMail gateways and peer mail servers) are always listed in the GBUdb ingore list even if the GBUdb database is lost for some reason. Every time the SNF Engine is started or loads a new configuration / rulebase, the IPs listed in the GBUdbIgnoreList.txt file are applied to the GBUdb database.

The GBUdb system identifies the source of an email by first skipping all Received headers that are listed in the GBUdb database with "Ignore" records. The first IP discovered in a message that is not ignored as part of your infrastructure is considered to be the source of the message.

The GBUdbIgnoreList.txt file contains a simple list of IPs, one IP per line.

# List of IPs to Ignore on startup
# Each IP in this list is set to Ignore in GBUdb when
# The configuration is loaded.
# Hash mark on the beginning of a line indicates a comment.
# Comments after an IP are also ignored.
# One line per IP. Sorry, no CIDR yet.
# Be sure to list ALL of your gateways :-)

127.0.0.1    # ignore localhost, of course.

You cannot list blocks of IPs in this file - it does not understand wild cards or CIDR. Only single IPs. If you need to specify blocks of IPs you should use the <drilldown/> feature to identify IP patterns that should be automatically ignored by GBUdb.