ping: sendto: No buffer space available

[Thomas Klausner <wiz%NetBSD.org@localhost>]

Hi!

I've recently switched from using re0 as main network device to ral0
with wpa_supplicant (amd64/5.99.55).

When I start rtorrent with ~20 torrents and an effective traffic of a
few 100KB/s, after a short while the machine falls off the net. When I
do ping then, I see
ping: sendto: No buffer space available

In a very old post I saw that increasing kern.mbuf.nmbclusters to 1024
might help, however, that value is already 262144 by default on this
machine.

For comparison, I also tried with an otus0. It survived a bit longer
before it had the same issue.
I also had two additional problems with otus0:
When in this state, I did
# ifconfig otus0 down
# ifconfig otus0 up
rather quickly, and got a kernel panic (I was in X so I didn't see
it).

Also, when unplugging otus0 immediately after booting (when the login
prompt is visible) I got:
otus0: could not send command 0x1 (error=IOERROR)
ehci_idone: ex=0xffff80001634d200 is done!
otus0: detached
otus0: at uhub7 port 5 (addr 4) disconnected

Suggestions on how to fix the buffer space issue? Or is it a bug in
the cards or drivers and can't be fixed?

Thanks,
 Thomas

[please CC me, I'm not on this list]