ntp is a time server you can use to synchronize the time across multiple machines connected to it. If you run a bunch of servers and they don’t all sync to the same time server, your logs will be screwy on them, especially if you try to reconstruct a network event using the logs by looking at the time stamp. This howto is done on Debian Wheezy, but will be similar on other distro’s
su apt-get install ntp |
Now make sure it’s getting times from the upstream time servers:
ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== y.ns.gin.ntt.ne 204.123.2.72 2 u 1 64 1 22.974 446456. 0.222 x.ns.gin.ntt.ne 204.123.2.72 2 u - 64 1 21.040 446455. 0.536 15.185.186.215 198.153.152.52 2 u 1 64 1 52.064 446456. 1.268 clock1.albyny.i .CDMA. 1 u - 64 1 84.155 446452. 0.168 |
This means it’s working. Now login to your other machines and use the IP of this NTP server as your time server, and check to see if it worked.