%ndd001f
This option determines whether to forward broadcast packets directed
to a specific net or subnet, if that net or subnet is directly
connected to the machine. If the system is acting as a router, this
option can be exploited to generate a great deal of broadcast network
traffic. Turning this option off will help prevent broadcast traffic
attacks.  
To disable this do:
 # ndd -set /dev/ip ip_forward_directed_broadcasts 0
%ndd002f
This option determines whether to forward packets that are source
routed. These packets define the path the packet should take instead
of allowing network routers to define the path.
To disable this do:
  # ndd -set /dev/ip ip_forward_src_routed 0
%ndd003w
IP forwarding is the option that permits the system to act as a router
and thus resend packets from one network interface to another. If your
system is not acting as such this option should be disabled.
To disable this do:
 # ndd -set /dev/ip ip_forwarding 0
%ndd004f
The echo-request PMTU strategy can be used for amplification attacks.
Use either strategy 1 or strategy 0.
To disable this do:
 # ndd -set /dev/ip ip_pmtu_straegy [0|1]
%ndd005w
This option determines whether to send ICMP redirect messages which
can introduce changes into remote system's routing table. It should
only be used on systems that act as routers.
To disable this do:
 # ndd -set /dev/ip ip_send_redirects 0
%ndd006w
The system is configured to send ICMP source quench messages.  These
ICMP messages have been deprecated.
To disable this do:
 # ndd -set /dev/ip ip_send_source_sqench 0
%ndd007f
This options determines whether to respond to ICMP netmask requests
which are typically sent by diskless clients when booting. An
attacker may use the netmask information for determining network
topology or the broadcast address for the subnet.
To disable this do:
 # ndd -set /dev/ip ip_respond_to_address_mask_broadcast 0
%ndd008f
This option determines whether to respond to ICMP broadcast echo
requests (ping). An attacker may try to create a denial of service
attack on subnets by sending many broadcast echo requests to which all
systems will respond. This also provides information on systems that
are available on the network.
To disable this do:
 # ndd -set /dev/ip ip_respond_to_echo_broadcast 0
%ndd009f
This option determines whether to respond to ICMP broadcast timestamp
requests which are used to discover the time on all systems in the
broadcast range. This option is dangerous for the same reasons as 
responding to a single timestamp request. Additionally, an attacker
may try to create a denial of service attack by generating many
broadcast timestamp requests.
To disable this do:
 # ndd -set /dev/ip ip_respond_to_timestamp_broadcast 0
%ndd010f
This option determines whether to respond to ICMP timestamp requests
which some systems use to discover the time on a remote system. An
attacker may use the time information to schedule an attack at a
period of time when the system may run a cron job (or other time-
based event) or otherwise be busy. It may also be possible predict
ID or sequence numbers that are based on the time of day for spoofing
services.
 # ndd -set /dev/ip ip_respond_to_timestamp 0
%ndd011w
This option determines if HP-UX will include explanatory text in the
RST segment it sends.  This text is helpful for debugging, but is also
useful to potential intruders.
To disable this do:
 # ndd -set /dev/tcp tcp_text_in_resets 0
