hubs and promiscuous packet listening

[Aaron Wohl]

Does anyone know the model number of a cheap hub to use when packet
sniffing?  The two suposed hubs I have seem to be blocking packets not
addressed to me same as a switch would...

I'm trying tcpdump and ipgrab as root via a hub to listen to anouther
computer.  The interface is going into promiscuous mode as ifconfig
shows:

  fxp0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu
  1500

But I cant see any traffic for the other machines on the hub.  I tried
listening on a linux box on the same hub with the same problem... I tried
a second hub, same problem.  One hub is a linksys EFAH05W the other is a
linksys NH1005.

I was wondering if linksys labeled a hub because only one packet can pass
thru it and a time and it has no buffereing but its still not spamming
each packet out all the ports like I want it to do for debugging?