[58455] in North American Network Operators' Group
Re: NTp sources that work in a datacenter (was Re: Is latency equivalent to RTT?)
daemon@ATHENA.MIT.EDU (Steven M. Bellovin)
Wed May 14 13:35:44 2003
To: Joel Jaeggli <joelja@darkwing.uoregon.edu>
Cc: Steve Francis <steve@expertcity.com>, Michael.Dillon@radianz.com,
nanog@merit.edu
Date: Wed, 14 May 2003 12:38:43 -0400
From: "Steven M. Bellovin" <smb@research.att.com>
Errors-To: owner-nanog-outgoing@merit.edu
In message <Pine.LNX.4.44.0305140802170.7544-100000@twin.uoregon.edu>, Joel Jae
ggli writes:
>
>
>Also if you just need a high level of syncronization between the time on
>all your hosts you can just deploy one standalone ntp server, sync it
>against public time sources and get everything synced against that. its
>probably a 95% solution to most people's timeing needs.
>
If I recall correctly, NTP assumes that latency = RTT/2. You might
make it work well for his application *if* you set up your tree so that
your paths are each one hop, or at least symmetric over your network.
--Steve Bellovin, http://www.research.att.com/~smb (me)
http://www.wilyhacker.com (2nd edition of "Firewalls" book)
