If you have Cisco core routers in your network, I have found them to be good NTP servers. Set them up with however many masters you want, there are nice ACL commands to limit clients and prevent amplification attacks. Should probably specify them by loopback address to insure they are reachable even if OSPF reconfigures path to router.
-----Original Message----- From: Af [mailto:[email protected]] On Behalf Of Chuck McCown Sent: Monday, October 10, 2016 10:21 AM To: [email protected] Subject: Re: [AFMUG] Update on DHCP - Calix failures Nice clock source. Thanks. I think I am going to buy the larger one. It has an onboard OCXO for holdover timing. -----Original Message----- From: Seth Mattinen Sent: Monday, October 10, 2016 8:55 AM To: [email protected] Subject: Re: [AFMUG] Update on DHCP - Calix failures On 10/10/16 7:32 AM, Chuck McCown wrote: > I am guessing that Xmission was giving us a malformed or otherwise > unpalatable NTP time hack. Calix reacted by setting the RTC to goofy > time. I have never dug into the internals of NTP. I guess the next > step would be to wireshark that and figure out what is going on. But > Calix should fall back to secondary NTP or freerun if it does not like > what it is getting. And give an alarm. How many tickers were configured? Good practice is to configure at least 4 from different sources so that NTP can detect a false ticker or bad time source. Configuring two is bad. If you only have the option to configure one or two NTP servers then only do one but sourcing off a time server that has at least four. NTP doesn't do "primary" or "secondary". These are cheap to have your own GPS clock: https://www.css-timemachines.com ~Seth
