Cisco WS-C4003 - Catalyst 4000 Chassis Switch Software Configuration Manual page 210

Chapter 12 Configuring Dynamic Port VLAN Membership with VMPS
Dynamic Port VLAN Membership with Auxiliary VLANs
This example shows that the auxiliary VLAN ID specified cannot be the same as the native VLAN ID:
Console> (enable) set port auxiliaryvlan 5/10 223
Auxiliary vlan cannot be set to 223 as PVID=223.
Console> (enable)
Software Configuration Guide—Catalyst 4000 Family, Catalyst 2948G, Catalyst 2980G, Releases 6.3 and 6.4
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