Since I am pro-Linux, we will start with Linux.
In Linux, TCP TimeStamp is enabled by default. You can check this by running this command.
[root@ares ~]# cat /proc/sys/net/ipv4/tcp_timestamps
If the returned result is equal to one then you are good to go, however if it is zero then you can enable TCP TimeStamp option instantly by running this command.
[root@ares ~]# echo 1 > /proc/sys/net/ipv4/tcp_timestamps
Run this command to make the setting persistent and survive a reboot.
[root@ares ~]# echo 'net.ipv4.tcp_timestamps = 1' >> /etc/sysctl.conf
Open "command prompt" by typing cmd in run. Make sure you are running it as administrator.
netsh int tcp set global timestamps=enabled
If you guys know how to do this for MAC/Solaris/Whatever else, please comment.