[tulip-bug] Linksys PCMPC200 requires PROMISC mode to recieve? [.92]

Scott A Crosby crosby@qwes.math.cmu.edu
Mon, 25 Sep 2000 02:02:41 -0400 (EDT)

Hello. I have a `Linksys EtherFast Cardbus 10/100' PCMCIA card. (Model
number: PCMPC200) that was bought a week ago. Although the most recent
version of the driver [.92] works without problems, for some reason, I
need to keep the card in promiscious mode

If I don't....

For example: From the perspective of another host on the network. (Here,, the laptop, is trying to ping the base station: dragonlight.

21:44:33.855332 arp who-has dragonlight tell
21:44:33.855374 arp reply dragonlight is-at 0:50:da:6c:c9:93
21:44:34.855302 arp who-has dragonlight tell
21:44:34.855344 arp reply dragonlight is-at 0:50:da:6c:c9:93

It is getting responses, but it's not using them for some reason.

Here, I am pinging to the laptop:

21:46:57.429317 arp who-has tell dragonlight
21:46:57.429457 dragonlight > icmp: echo request
21:46:58.429426 arp who-has tell dragonlight
21:46:58.429515 dragonlight > icmp: echo request

dragonlight is using it's ARP cache to try satisfy the requests. It's also
trying to verify that it's ARP entry is accurate with the additional ARP

The symptoms seem as if the ethernet card isn't sending packet's to the
kernel unless PROMISC mode is set. When PROMISC is set, all this
automagically goes away.

I'm starting the network card with:
  ifconfig eth0 netmask broadcast promisc arp up
  route add -net netmask eth0

Which should have been all I needed. If I make it '-promisc', I get the
above failures.

Here's 'ifconfig' for when in PROMISC mode and it works.

eth0      Link encap:Ethernet  HWaddr xx:xx:xx:xx:xx:xx
          inet addr:  Bcast:  Mask:
          UP BROADCAST RUNNING PROMISC  MTU:1500  Metric:1
          RX packets:667 errors:0 dropped:0 overruns:0 frame:0
          TX packets:631 errors:6 dropped:0 overruns:6 carrier:1
          collisions:0 txqueuelen:100 
          Interrupt:3 Base address:0xe000 

hypercube:/usr/src/linux# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface        *          U     0      0       0  eth0        *          U     0      0       0  eth0

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