Article 4946 of comp.protocols.time.ntp: Path: mri.com!news.aimnet.com!netserv.com!news.clark.net!world1.bawave.com!newsfeed.internetmci.com!in1.uu.net!EU.net!Belgium.EU.net!news.eurocontrol.be!cfmu!postmaster From: rid@pst.cfmu.eurocontrol.be (Jim Reid) Newsgroups: comp.protocols.time.ntp Subject: Re: Practical NTP configuration for ~200 UNIX machines? Date: 30 May 1996 12:47:08 +0200 Organization: Eurocontrol, Brussels Lines: 45 Sender: rid@heron.pst.cfmu.eurocontrol.be Distribution: inet Message-ID: References: <31AC6E51.41C6@cadcam.pd9.ford.com> NNTP-Posting-Host: heron.pst.cfmu.eurocontrol.be In-reply-to: "John D. Jamulla"'s message of Wed, 29 May 1996 11:33:37 -0400 X-Newsreader: Gnus v5.1 >>>>> "John" == "John D Jamulla" writes: John> I am looking for "advice" on the best way to configure and John> use ntp in the following setup: John> 1. Should we (is it even possible) to use ntp on the server John> machine in broadcast mode? Recent versions of xntpd support NTP broadcasting and multicasting. Whether you use these or not depends on your local environment and your religious preferences. For example, broadcast or multicast NTP packets are BAD if the ntp daemon is demand paged across the net. When someone broadcasts or fires off a multicast NTP packet, all the hosts running NTP iwill simultaneously wake up their NTP daemons and have them demand page the probably swapped out NTP daemon from the file/swap server(s). Nasty. Generally speaking, it is best to avoid unnecessary broadcasts because EVERYTHING on your net sees and has to process these packets, even if only to discard them. Multicasting is preferable, but not all systems and network interfaces are capable of supporting this. John> 2. Should I be using peers, and how do I pick those peers? Yes. Organise a hierarchy. Get 3 or 4 of your best timekeepers to act as Stratum-N servers. These are the only ones to peer with off-site servers and/or have radio clocks. Have these stratum-N servers feed time to another set of systems: say each "cluster" file server. These stratum N+1 servers peer with each other and the stratum N servers. End workstations and PCs peer with the N+1 stratum servers (or N+X where X > 2 if you have a large enough network. John> 3. How do you find the correct tickadj and precision values? Wave a few chicken bones, sacrifice a virgin, that sort of thing. It depends on kernel behaviour that vendors like to keep to themselves and change from release to release. The installation/config scripts for recent xntpd distributions will automatically set these to reasonable values for common hardware and OS platforms. John> 4. Does anyone have a practicality guide to how many servers John> per number of clients and other "real life" infomation? Yes: read the documentation that comes with the xntpd distribution. It answers all the commonly asked questions, including those above.