Andy,
That's normal output. Cat4500 does show the same for dynamic mac-addresses. This is the output from my lab switch :
Energywise#show mac address-table dynamic
Unicast Entries
vlan mac address type protocols port
-------+---------------+--------+---------------------+--------------------
85 0000.0c07.ac55 dynamic ip,ipx,assigned,other GigabitEthernet2/48
85 0010.f31a.023f dynamic ip,ipx,assigned,other GigabitEthernet2/15
85 0023.5ec9.6b18 dynamic ip,ipx,assigned,other GigabitEthernet2/48
85 0050.6004.2bc5 dynamic ip,ipx,assigned,other GigabitEthernet2/4
85 0050.6004.4f94 dynamic ip,ipx,assigned,other GigabitEthernet2/7
I would look for few things here :
1. CPU utilization -> Please paste the output of " Show proc cpu "
2. Memory Utilization -> Please paste the output of " Show proc mem "
3. Interface errors and drops, if any.
4. Logs -> Please paste the output of "show logging "
5. Spanning-tree loop on the network -> Please paste the output of " show spanning-tree details "
Please have all these outputs attached to a file.
Cheers,
-amit singh