Hi~
Which do you use any OS, CatOS or IOS?
If you use CatOS,
"C6509(enable) sh cam dynamic ".
If you use IOS,
" C6509#sh mac-address-table dynamic interface fastEtherne"
If the MAC address be showed up More than 1 address on the port, it is cleary HUB.
EX)
C6509#sh mac-address-table dy int fa 6/24
Unicast Entries
vlan mac address type protocols port
-------+---------------+--------+---------------------+--------------------
160 0000.f09b.068d dynamic ip FastEthernet6/24
160 0000.f09b.6749 dynamic ip FastEthernet6/24
160 0004.9aaa.c500 dynamic ip FastEthernet6/24
160 000d.9dfe.ce2c dynamic ip FastEthernet6/24
160 0012.3f7d.fc2d dynamic ip FastEthernet6/24
160 0013.7710.877f dynamic ip FastEthernet6/24
160 0013.771b.6369 dynamic ip FastEthernet6/24
160 0013.778b.9579 dynamic ip FastEthernet6/24
160 0013.77c6.d3be dynamic ip FastEthernet6/24
160 0015.9923.8ab5 dynamic ip,ipx FastEthernet6/24
160 0030.6eea.13a8 dynamic ip FastEthernet6/24
C6509#
In case of this will spend many time.