NTP broadcast mode in combination with datadiode

[Wejoosten]

When i use NTP broadcast mode with a datadiode in between, the client will not sync the time because of a initial volley back to the server. This means that the broadcast client is operating in normal client mode to exchanges packets with the server. It's calibrating the propagation delay and run the autokey security protocol (RFC5905) after it reverts to broadcast client mode. When a datadiode is between the broadcast server and client traffic can only go one way. Is there a feature or a fix to resolve this problem? 

[paul driver]

Hello

I am assuming if your not allowing return traffic through that datadiode NTP will not synchronize, what you don't mention is what you have connected between this datadiode, is it a cisco router/switch and what device is running as the NTP stratum? 

[Wejoosten]

Paul thank you for your reaction. I tried several options. A router as NTP master (stratum 1,2,3), a switch as ntp master (stratum 1,2,3) but is not working. Only when i tried an old 7200 it was working but that is not an option. Now i have a real time server (stratum 1) with a gps antenna and this server is connected to a c9300 with the datadiode in between. 

[mickey_ko]

Hi Wejoosten:

Was the issue of NTP broadcast on c9300 with a datadioade  between it and the master clock ever resolved? We used to work that way with catalyst switches but with c9300  NTP seems to have been changed.

I would appreciate  your insight or any one else's.

thanks

mickey.