I cannot reach a certain remote IP address from my Mac. Pinging it gives "Request timeout" and after 4 or 5 pings "No route to host" and "Host is down". The weird fact is that other Macs on my same local network can access it without problems. I don't have any firewall active, nor Little Snitch or similar, nor proxies, nor /etc/hosts tricks (which deal only with host name resolutions, anyway, but I have to reach the IPv4 address). I have a 2011 13" MacBook Air with OS X 10.7.5. Can you point me to some other obscure network settings or blocking lists that may be active on Mac Os X or maybe some software that may interfere with network settings? Thank you.
The problem lies on the LogMeIn Hamachi network which, on IPv4, tries to get all the 18.104.22.168/8 netblock even if there are classes opf public IP addresses in there. Solved by setting LogMeIn to use IPv6 only.