No Ip & sniffing

Hy, my question is fairly simple, but the anwser looks difficult. First, my Setup: * SuSe Linux 7.0 running on a PII 350 * Snort 1.8.1 * Network Card Lance (AMD 79c961) Now, my problem, i am trying to setup a no-ip interface, what i found in the internet was that all i needed to do was: ifconfig eth1 up promisc and after this the NIC seems to capture all the traffic, but it drops it, in ifconfig i see the droped count rise, i am asking this in this mailing list because the problem may be suse specific (and it is about security, i think), but i can't find information about what may be causing this. Jose Araujo