Re: [ntp:questions] NTP access restrictions IPv6

2019-02-28 Thread Dan Geist
Hi, Philippe. First, off, the following pages are very useful for understanding security controls in detail: https://support.ntp.org/bin/view/Support/AccessRestrictions https://www.eecis.udel.edu/~mills/ntp/html/accopt.html I'll try to answer the questions: a) Generally, it looks pretty good. You

Re: [ntp:questions] Detecting ntp broadcast packets

2019-02-28 Thread Miroslav Lichvar
On Wed, Feb 27, 2019 at 08:39:45AM -0900, John Thurston wrote: > And since I'm on a switched ethernet LAN, my network port is only going to > see traffic destined for my own MAC (or broadcast) anyway. So I really can't > see any benefit to enabling promiscuous mode. What am I missing? Nothing. I w

Re: [ntp:questions] Detecting ntp broadcast packets

2019-02-28 Thread John Thurston
On 2/26/2019 11:34 PM, Miroslav Lichvar wrote: On Tue, Feb 26, 2019 at 09:58:06AM -0900, John Thurston wrote: B) use snoop or tcpdump to look at broadcast packets and tell me if it uncovers any ntp Is there already a better way to watch and warn of such packets? An easier way would be to use

[ntp:questions] NTP access restrictions IPv6

2019-02-28 Thread Philippe Maechler
Hello List I'm setting up a few pairs of new ntp servers for our network. The setup is like that: +-++-+ +| s1-ntp1 || s1-ntp2 |+ |+-++-+| | | | |