HP-UX IPFilter Version A.03.05.14 Administrator's Guide
HP-UX IPFilter Configuration Examples
BASIC_1.FW
Appendix A 149
BASIC_1.FW
#!/sbin/ipf -f -
#
# SAMPLE: RESTRICTIVE FILTER RULES
#
# ppp0 - (external) PPP connection to ISP, address a.b.c.d/32
#
# lan0 - (internal) network interface, address w.x.y.z/32
#
# This file contains the basic rules needed to construct a
# firewall for the above connections.
#
#-------------------------------------------------------
# Block short packets which are packets fragmented too short to
# be real packets.
block in log quick all with short
#-------------------------------------------------------
# Group setup.
# ============
# By default, block and log all packets. This may result in
# too much information to be logged (especially for lan0)
# and needs to be further refined.
#
block in log on ppp0 all head 100
block in log proto tcp all flags S/SA head 101 group 100
block out log on ppp0 all head 150
block in log on lan0 from w.x.y.z/24 to any head 200
block in log proto tcp all flags S/SA head 201 group 200
block in log proto udp all head 202 group 200
block out log on lan0 all head 250
#-------------------------------------------------------
# Localhost packets.
# ==================
# Packets going in/out of network interfaces that aren’t on the
# loopback interface should *NOT* exist.
block in log quick from 127.0.0.0/8 to any group 100
block in log quick from any to 127.0.0.0/8 group 100
block in log quick from 127.0.0.0/8 to any group 200
block in log quick from any to 127.0.0.0/8 group 200
#-------------------------------------------------------
# Invalid Internet packets.
# =========================