[9fans] OT: 3c590C, 3c509B-C repeated carrier loss with e-tech wireless router

[Axel Belinfante <Axel.Belinfante@cs.utwente.nl>]

Off-topic question (partly on-topic because plan 9 is one of the
O.S.'es demonstrating the problem (I also tried linux and windows 98)).

This quesion is about a wireless router (brandname: E-tech,
http://www.e-tech.nu/), that includes a four-port 10-100Mbit switch.
When I connect the subject-mentioned (10Mbit) 3com etherlink III cards
to it, the link comes up nicely, but when I start to ping the router,
in a couple of seconds (after a couple of packets) the link goes down,
comes up after 2-3 seconds, works for a while, gets down again,
comes up etc., packet loss 30%-40%.
Shifting the pci card to another slot, or removing all other cards
(except for the video card) dit not make a noticable difference.

Connecting such a 3com card via a cross link cable to another machine,
it works ok. Also with our normal (university/faculty) net it works ok.

I tried the wireless router with four other cards, which worked fine:
one 10Mbit that linux identified as realtek 8029 pci (ne2k-pci driver)
one 100Mbit that plan 9 identified as i82557,
a 10Mbit xircom rem56g10 realport ethernet+modem (with linux),
and a 10-100mbit pcmcia card (in linux, which reported autonegotiated
half-duplex)

Any ideas, anyone? (I suspect some sort of auto-negotation failing?)

3com card details:
   3c590C  (pci, combo) 03-0046-000 rev A
   3c509B-C (isa, combo) assy 03-0021-002 rev A


Axel.