freebsd-dev/etc/ppp/ppp.conf.filter.sample

#
# $Id: ppp.conf.filter.sample,v 1.4 1997/02/23 09:21:10 peter Exp $
#
# An example of packet filter definitions.  Merge whatever rules you
# want into your ppp.conf file.
#
filterd:
#       
# Don't keep Alive with ICMP,DNS and RIP packets
#
 set afilter 0 deny icmp
 set afilter 1 deny udp src eq 53
 set afilter 2 deny udp dst eq 53
 set afilter 3 deny udp src eq 520
 set afilter 4 deny udp dst eq 520
 set afilter 5 permit 0/0 0/0
#
# Don't let ICMP packets cause us to dial
#
 set dfilter 0 deny icmp
 set dfilter 1 permit 0/0 0/0
#
# Allow ident packets to pass through
#
 set ifilter 0 permit tcp dst eq 113
 set ofilter 0 permit tcp src eq 113
#
# Allow telnet connections to the Internet
#
 set ifilter 1 permit tcp src eq 23 estab
 set ofilter 1 permit tcp dst eq 23
#
# Allow ftp access to the Internet
#
 set ifilter 2 permit tcp src eq 21 estab
 set ofilter 2 permit tcp dst eq 21
 set ifilter 3 permit tcp src eq 20 dst gt 1023
 set ofilter 3 permit tcp dst eq 20
#
# Allow access to any DNS
#
 set ifilter 4 permit udp src eq 53
 set ofilter 4 permit udp dst eq 53
#
# Allow access from/to my company network
#
 set ifilter 5 permit 192.244.191.0/24 0/0
 set ofilter 5 permit 0/0 192.244.191.0/24
#
# Allow ping and traceroute response
#
 set ifilter 6 permit icmp
 set ofilter 6 permit icmp
 set ifilter 7 permit udp dst gt 33433
 set ofilter 7 permit udp dst gt 33433
#
# If none of the above rules matche, then the packet is blocked.
#