I haven't been able to find anyone else with this problem after searching Google and others. I'm wondering if I'm just doing something wrong.
I have two hosts, connected via crossover cable, and I am running: dd if=/dev/zero bs=131072 | nc -u 10.0.0.3 8000 on one and nc -l -p 8000 -s 10.0.0.3 -u > /dev/null on the other. "netstat -i" and ifconfig both show packet counts increasing, and on both ends tcpdump shows either the packets leaving the host or coming to the host, respectively. On neither host does iptraf report anything more than one or two UDP packets in "IP Traffic monitor", "General interface statistics", "Detailed interface statistics" or "Statistical breakdowns". It does see the traffic when using "LAN Station monitor" mode. There are no filters applied in the iptraf "Filters" menu (specifically, it says "All UDP visible"). It's missing around 800Mbit/s, according to the stats dd gives when you ^C it. Both hosts are identical, and are running kernel 2.6.14.3 and Debian Sarge, using the Intel 82541GI/PI NIC, negotiated at 1000Mbps. Here's a snip of what tcpdump is seeing: 18:07:32.039438 IP 10.0.0.2 > 10.0.0.3: udp 18:07:32.039458 IP 10.0.0.2 > 10.0.0.3: udp 18:07:32.039559 IP 10.0.0.2 > 10.0.0.3: udp 18:07:32.039577 IP 10.0.0.2.32769 > 10.0.0.3.8000: UDP, length: 8192 18:07:32.039686 IP 10.0.0.2 > 10.0.0.3: udp 18:07:32.039704 IP 10.0.0.2.32769 > 10.0.0.3.8000: UDP, length: 8192 18:07:32.039815 IP 10.0.0.2 > 10.0.0.3: udp 18:07:32.039818 IP 10.0.0.2 > 10.0.0.3: udp 18:07:32.039934 IP 10.0.0.2 > 10.0.0.3: udp 18:07:32.039937 IP 10.0.0.2 > 10.0.0.3: udp 18:07:32.039954 IP 10.0.0.2.32769 > 10.0.0.3.8000: UDP, length: 8192
