custom ICMP message in iptables

[Jatin K]

Dear all,


I'm wondering that, is there any method to add custom ICMP message to 
iptables ... e.g  say I block Echo Request (ping) through 
system-config-firewall, other systems on my network cannot ping my 
system ...  but on on the system from where I try to ping .. it shows 
message like  [1]

[1] From xxx.xxx.xxx.xxx icmp_seq=xxx Destination Host Prohibited
      From xxx.xxx.xxx.xxx icmp_seq=xxx Destination Host Prohibited
      From xxx.xxx.xxx.xxx icmp_seq=xxx Destination Host Prohibited
      From xxx.xxx.xxx.xxx icmp_seq=xxx Destination Host Prohibited

problem is that anyone can determine that my system is alive and icmp 
request is blocked


instead  of this I want like this [2]

[2]  From xxx.xxx.xxx.xxx icmp_seq=xxx Destination Host *Unreachable *
       From xxx.xxx.xxx.xxx icmp_seq=xxx Destination Host *Unreachable *
       From xxx.xxx.xxx.xxx icmp_seq=xxx Destination Host *Unreachable *
       From xxx.xxx.xxx.xxx icmp_seq=xxx Destination Host *Unreachable
*