On a 3.0.1 machine, I received the message 'ex0: uplistptr was 0'.  At
about the same time, 327 input errors were recorded in a 15 second
interval.  That latter was contemporaneous with a spike of 11444 packets
received in the same slot.  What's going on?  Is there something I need to
worry about or retune?  (The normal input load is much lower than that,
but in ttcp stress tests I've sent 120K packets per 15 seconds to
the machine without causing any trouble.)

Here's the dmesg for the card at boot time:

ex0 at pci1 dev 7 function 0: 3Com 3c905C-TX 10/100 Ethernet with mngmt
(rev. 0x78) ex0: interrupting at irq 5
ex0: MAC address 00:04:76:23:71:03
exphy0 at ex0 phy 24: 3Com internal media interface

The code seems to suggest the message is related to running out of upload
descriptors for DMAing input into memory, but what might trigger that,
given that the machine can handle 10x that load without problem?

		--Steven M. Bellovin, http://www.cs.columbia.edu/~smb