"aborting pdelay calculation" filling logs

My logs are continually streaming messages about "pdelay", here is an excerpt:

Jun 2 11:17:35 xxxs-MacBook-2015 kernel[0]: IO8021ASEthernet(en4): t4 = 1433258255847358072 t1 = 1433258255845622545 pdelay_exchange_time = 1735527

Jun 2 11:17:35 xxxs-MacBook-2015 kernel[0]: IO8021ASEthernet(en4): t3 = 4461233342225 t2 = 4461231657703 pdelay_response_time = 1684522

Jun 2 11:17:35 xxxs-MacBook-2015 kernel[0]: IO8021ASEthernet(en4): fPDelayNeighborInterval[2] = 6093598072, fPDelayLocalInterval[2] = 6093595196

Jun 2 11:17:35 xxxs-MacBook-2015 kernel[0]: IO8021ASEthernet(en4): raw_2xpdelay_ns = 51005

Jun 2 11:17:35 xxxs-MacBook-2015 kernel[0]: IO8021ASEthernet(en4): raw_2xpdelay_ns for sequence ID = 1837 is ridiculously big. Aborting pdelay calculation.

Jun 2 11:17:36 xxxs-MacBook-2015 kernel[0]: IO8021ASEthernet(en4): Timestamps are out of order. Skipping pdelay calculation.

Jun 2 11:17:36 xxxs-MacBook-2015 kernel[0]: IO8021ASEthernet(en4): t1=1433258256849084689 t2=1433258261502951728 t3=1433258256301852361 t4=1433258256849301008

Jun 2 11:17:36 xxxs-MacBook-2015 kernel[0]: IO8021ASEthernet(en4): pdelay_response_time (13302881761) >= pdelay_ppm_limit (216362) [pdelay_exchange_time (216319)]. This makes no sense. Aborting pdelay calculation.

Jun 2 11:17:36 xxxs-MacBook-2015 kernel[0]: IO8021ASEthernet(en4): pdelay_response_time (7040079697) >= pdelay_ppm_limit (289360) [pdelay_exchange_time (289303)]. This makes no sense. Aborting pdelay calculation.

Jun 2 11:17:36 xxxs-MacBook-2015 kernel[0]: IO8021ASEthernet(en4): t4 = 1433258256849446264 t1 = 1433258256849084689 pdelay_exchange_time = 361575

This is a new Macbook Pro 15" retina (the latest model) with Thunderbolt to gigabit ethernet, which is the (en4) adapter showing in the logs.

Any ideas why this is happening?

OS X 10.10.3, 16 GB RAM, fresh clean install of system.