Packets control.

["Boris Bar" <barboris () hotmail com>]

Hello All,

1)How can I set to the null value a particular packet?

2)Should flexible response (FlexResp) block a connection?
If yes, why packet is received after I set
   alert icmp any any -> 192.168.1.0/24 any (resp: icmp_port,icmp_host;  
   msg: "Need block ICMP";) .

3)I read that snort should be set both before and after firewall, but I don't know
how to set it after the firewall. I want to be sure that nothing bad passed
through the firewall. 

Thanks ,
Boris.