VT6120 Gigabit Ethernet Adapter not passing multicast traffic
I have a VIA motherboard here with a VT6120 Gigabit Ethernet Adapter (onboard). This is the strangest thing:
I do a CentOS 5.x install and run the yum -y update - (I can list all of the packages in my kickstart file if need be) and I reboot once the install is completed ( of course)
Now, the application that I am running on it needs to pass multicast traffic on tcp ports 5000 and 5001.
I don't see any m-cast traffic UNTIL I run wireshark, tcpdump , tshark , or some other sniffing tool. So, I think that the key here is once the eth0 is put in promiscuous mode, I see multicast traffic.
It still works after I reboot, shut down , log out , whatever.
No firewall, SELinux is disabled on boot.
Anyone see anything like this before?