Hi there, I'm currently experiencing a strange issue with my MAC book pro Snow Leopard. My MAC won't reply back to ping commands issued on other hosts within the same network. From IP stand point of view all is good all the hosts are within the same subnet 192.168.1.0/ 255.255.255.240. I was pinging from two other machines the MAC's IP address and no reply back at all. When pinging from my MAC the other hosts, I get the ICMP replies I have switched off the firewall, and also while the firewall was on I have unchecked the stealth mode, no results. I've created a new location and no ICMP replies when pinging MAC 's ip address from the other machines within the network. In attempt to isolate the issue I directly connected the MAC with another computer via a crossover cable, and got the same symptoms Is it there a UNIX command that will reset the TCP IP socket. ICMP is part of the TCP IP stack and reinstalling or resetting the socket should fix the problem...I guess ) Or is there a command in UNIX that can force deactivating the firewall. Reinstalling the whole OS or deleting the system preferences settings is like using a hammer in stead of scalpel. Thank you in advance for your advice and patience.