Hier zu Deiner Frage im PS: die "internal vlans"
Cisco Systems, Inc
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The following information applies to VLAN ranges:
•Layer 3 LAN ports, WAN interfaces and subinterfaces, and some software features use internal VLANs in the extended range. You cannot use an extended range VLAN that has been allocated for internal use.
•With Release 12.1(13)E and later releases, to display the VLANs used internally, enter the show vlan internal usage command. With earlier releases, enter the show vlan internal usage and show cwan vlans commands.
•With Release 12.1(13)E and later releases, you can configure ascending internal VLAN allocation (from 1006 and up) or descending internal VLAN allocation (from 4094 and down). In previous 12.1EX releases that support 4096 VLANs, internal VLANs are allocated from 1006 and up.