Hello Managers, thanks for the quick reply.
To forward or not to forward ? ( sounds familiar )
My problem was how to make sure that a host connected to 2 networks
(in my case - one local and one to the internet)
won't forward tcp/ip packets between networks.
The answer: It depends on the kernel parameter IPFORWARDING (1=yes, -1=no)
Thanks to the quick replys from :
   Nate Itkin <Nate-Itkin@ptdcs2.intel.com>.
   Sharon Buller - Sys Adm Team (1723)" <sharon@telecomm.tadiran.co.il>
Attached is the detailed explanation of Nate Itkin:
Look at /sys/netinet/in_proto.c.  Possible values for IPFORWARDING are:
        ip_forwarding == -1  -- never forward; never change this value.
        ip_forwarding ==  0  -- don't forward; set this value to 1 when two
                                or more interfaces are up.
        ip_forwarding ==  1  -- always forward.
The Sun default is 0.  To change the default to -1, edit your kernel config 
file (/sys/`arch -k`/conf/MYSUN) and add the following line:
           options IPFORWARDING=-1
Rebuild your kernel.  Or use adb on your existing kernel:
  mysun% echo "ip_forwarding/W -1" | adb -k -w /vmunix /dev/mem
  mysun% echo "ip_forwarding?W -1" | adb -k -w /vmunix /dev/mem
The first command modifies the running kernel and the second command
modifies the disk copy of vmunix so that when you reboot, the change
is saved.  Enjoy.
-- - Nate Itkin - Portland Technology Development, Intel Corporation Aloha, Oregon - E-mail: Nate-Itkin@ptdcs2.intel.com
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