On 4/3/19 3:32 PM, brutal8z via NANOG wrote:
I've not seen any mention of this here, so it might be off-topic, if so, sorry in advance. If you use GPS for time synchronization, this might be important.The Juniper ACX500 series and the Cisco 819 both have an embedded GPS receivers, for example.
At 23:59:42 UTC on 4/6/2019 (Midnight GPS time, which differs by 18 leap-seconds <https://en.wikipedia.org/wiki/Leap_second> from UTC) , the 10-bit GPS Week Number broadcast by the constellation will reset to zero for the second time since the beginning of GPS on 1/6/1980.
There was a mention of this a couple of weeks ago, as a "heads-up". When it first appeared up here, I checked with the vendor of my GPS time appliances. The vendor told me that the testing they did of their product showed no issues with the roll-over for specific ranges of serial numbers. Mine is within one of the ranges. The proof of the pudding will be what happens at 5pm PDT on my birthday, April 6, and what ntpq reports on my edge server.