action.drop

sharewall is very good

#
# Shorewall version 4 - Drop Action
#
# /usr/share/shorewall/action.Drop
#
#	The default DROP common rules
#
#	This action is invoked before a DROP policy is enforced. The purpose
#	of the action is:
#
#	a) Avoid logging lots of useless cruft.
#	b) Ensure that 'auth' requests are rejected, even if the policy is
#	   DROP. Otherwise, you may experience problems establishing
#	   connections with servers that use auth.
#	c) Ensure that certain ICMP packets that are necessary for successful
#	   internet operation are always ACCEPTed.
#
# IF YOU ARE HAVING CONNECTION PROBLEMS, CHANGING THIS FILE WON'T HELP!!!!!!!!!
#
###############################################################################
#TARGET		SOURCE	DEST	PROTO	DPORT	SPORT
#
# Count packets that come through here
#
COUNT
#
# Reject 'auth'
#
Auth/REJECT
#
# Don't log broadcasts
#
dropBcast
#
# ACCEPT critical ICMP types
#
AllowICMPs	-	-	icmp
#
# Drop packets that are in the INVALID state -- these are usually ICMP packets
# and just confuse people when they appear in the log.
#
dropInvalid
#
# Drop Microsoft noise so that it doesn't clutter up the log.
#
SMB/DROP
DropUPnP
#
# Drop 'newnotsyn' traffic so that it doesn't get logged.
#
dropNotSyn	-	-	tcp
#
# Drop late-arriving DNS replies. These are just a nuisance and clutter up
# the log.
#
DropDNSrep
#LAST LINE -- ADD YOUR ENTRIES BEFORE THIS ONE -- DO NOT REMOVE