Tracking Internet Computers

[Jason Stephenson]

Just answered my own question. On FreeBSD, there is a sysctl MIB to 
activate or deactivate RFC 1323 timestamping:

net.inet.tcp.rfc1323

Setting it to 1, the default, turns it on, setting it to 0, turns it off.

Looking at my OpenBSD machine, I see the same sysctl MIB as FreeBSD.

Finally, checking my laptop with Linux kernel 2.4.20, I find 
net.ipv4.tcp_timestamps, which likely has the same effect.

So, if you're worried about the technique being used on you, set those 
sysctl MIBs to 0, and don't worry about it. ;)