See the following link to Cisco:
http://www.cisco.com/warp/customer/473/34.shtml#MCAST_SOURCE_MAC
If you can't read that here is text:
%SYS-4-P2_WARN: 1/Invalid traffic from multicast source address
Problem: The switch is generating "Invalid traffic from multicast source address" messages.
Platform: Catalyst 4000 family switches
The following is an example of the syslog output you will see when this error occurs:
%SYS-4-P2_WARN: 1/Invalid traffic from multicast source address 81:00:01:00:00:00 on port 2/1
%SYS-4-P2_WARN: 1/Invalid traffic from multicast source address 81:00:01:01:00:00 on port 2/1
The "Invalid traffic from multicast source address" syslog message is generated when the switch receives packets with a multicast MAC address as the source MAC. Using a broadcast or multicast MAC address as the source MAC for a frame is not standards-compliant behavior. However, the switch still forwards traffic sourced from a multicast MAC address.
The syslog message indicates the multicast MAC address in the source MAC field of the frame, and the port on which the traffic was received.
The workaround is to try to identify the end station that is generating frames with a multicast source MAC address. Typically, such frames are transmitted from a traffic generator (for example, SmartBits) or third party devices that share a multicast MAC address (for example, load balancing firewall or server products).
This also may be associated with code problems as well so you may want to dig into your syslog files and look for other questionable messages. In our case, a Cat2926 switch was also getting EARL-2:LKUPRAM (Cisco bug ID CSCdk75035) errors.
That was a "blackcomb" parity error as we later found out (bug id CSCdk75035), caused the switch to create/propagate the "invalid traffic" (SYS-4-P2_WARN.
Fix: Code upgrade on affected switches. Note Cat2926 is a fixed chassis Cat5002. Code you put on will depend what your switch can support & your requirement but I'd recommend GD only 4.5(13a) or 5.5(13a).
