You can set up port mirroring and hook an analyzer/sniffer/wireshark
to a mirrored port, then filter all traffic except the MAC you are interested in.
Search for Port Mirroring in the admin guide:
http://www.cisco.com/en/US/docs/routers/csbr/rvs4000/administration/guide/RVS4000_Admin_Guide.pdfGood Luck