I noticed that under 3.99.3 my i810 board with

fxp0 at pci1 dev 1 function 0: i82559 Ethernet, rev 8
inphy0 at fxp0 phy 1: i82555 10/100 media interface, rev. 4

keeps fliping the link on and off at the switch. If the chip is doing
something, it doesn't happen, but if it's idle, about every 11-12 seconds
the link goes off, stays off for a second, then renegotiates. 2.0.2 does
not do this. It occurs with both the ROM code, and with loading the link0
code. Is anyone else seeing this?

I also am seeing this on a PowerEdge 2550. Except here, the link flips on
and off even if I am sending packets down the wire. The Cisco at the other
end of the cable really doesn't like this and makes the interface
unusable.