I think you are right, I see lots of ARP traffic on the failing ones and then :
# ip -s neigh show
10.227.145.1 dev eth0 ref 2 used 375/487/373 FAILED
On the good ones see either a couple of ARP packets (neighbor table empty or stale or I flushed it) or nothing (the table entry is still good) and then after it's marked REACHED.
Thanks, time to find out who owns the switch and if we can do anything about it.
Brandon