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

[Scott A Crosby]

On Mon, 25 Sep 2000, Neale Banks wrote:

> On Mon, 25 Sep 2000, Scott A Crosby wrote:
> 
> > 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
> [...]
> > 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.
> [snip]
> 
> This sounds similar to a problem I had with NetGear cards which was
> diagnosed by Keith Owens.  It only manifiested itself on shared media
> (i.e. hub not switch) and turned out to be that the arp-reply was never
> making it into the NIC's Rx ring (instead there was a copy of the
> transmitted packet).
> 
> 1) Are you on a hub?
> 

Actually, no. I'm on a crossover cable. (It's a new laptop, and I'm
setting stuff up and doing gigabytes of IO. The hub is only 10baseT.

> 2) Can you avoid this by first pinging *to* 10.2.3.5 (before 10.2.3.5 has
> attempted to arp)?
> 

No.. The echo reply's just fail to come back.

> 3) Does this silliness goes away if you put a static ARP entry on
> 10.2.3.5?
> 

DOUBLY strange.. Here's a new ping with both caches empty:

(hypercube is the laptop, 10.2.3.5)


12:43:07.111175 arp who-has hypercube. tell dragonlight.
12:43:08.108127 arp who-has hypercube. tell dragonlight.
12:43:08.108247 arp reply hypercube. is-at x:xx:xx:xx:xx:xx
12:43:08.108289 dragonlight. > hypercube.: icmp: echo request

crosby@dragonlight:~$ arp
Address                 HWtype  HWaddress           Flags Mask Iface
hypercube.              ether   xx:xx:xx:xx:xx:xx   C eth0

So the laptop is replying to the arp and filling in the cache. WHen I then
proceed to ping the laptop, the pings are sent, but the laptop is not
replying to them and is not sending out an ARP request TO reply to.

Not applicable.

Because I expect to use this laptop on several networks. both home and
elsewhere, I'me running a private DHCP server. That is failing too, and it
comes in before ARP.

Diagnosing the above, it appears as if the linksys network card is not
sending packets to the CPU unless they're broadcast or the card is set
promisc. This is either a driver bug, or I am making some mistake setting
up the card with my IP address. (See my last email for the lines I use)


Scott

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