If you have 15.1 installed you will require a NTP XMOD to configure NTP. With the correct entitlement this can be found on the support website. This is better explained in the article below:
Will do, but anything that didn't get updated this summer will likely wait until next. Seems school breaks get shorter all the time (all way more gear to keep updated).
Thank you!
To add to what Patrick has mentioned here, EXOS versions less than 15.4 are near or have already reached End-of-Support.
Have a look at the Recommended Release document (due for an update soon!)