block ping from host to host using iptables (I am the wireless access point)

view story

http://www.linuxquestions.org – I'm really new to networking and linux system. So please help me in this: - I have my phone acted as the wireless access point, and other devices like all my LAPTOPs connected to it to create a LAN network. How can I use iptables to block (for example ping request, reply) from host to host. P/s: I also try to block forward chain using iptables -A FORWARD -j DROP But it doesn't work. Host A can still ping to Host B. The blocking forward chain only helps me to block them (hosts in LAN) access the internet. (HowTos)