MAC level type of packet and cannot be viewed using the SPAN feature?

[mgupta]

Can someone ellaborate the statement "MAC level type of packet and cannot be viewed using the SPAN feature " as mentioned in one of the Cisco document. Actually I am facing a problem that the traffic received on a switch port from another ISP switch is not being copied to destination port using a SPAN session. The source port RX shows approx 800 Mbps traffic and packets also but destination port counters remain zero. Is it the traffic type which this switch where SPAN session is configured , is not able to recognized and therefore not able to copy on destination port? Thanks

[Antonio Knox]

Let's start with details.  What interface (FastEthernet x/y) are you attempting to mirror with SPAN?  Post your monitor config.  I can evaluate what you are trying to achieve and let you know what you may need to review and/or change.