Hi,
Extended VLANs can't be configured from the vlan database mode, and must be configured from the global configuration mode.
Rack1SW1#vlan database
% Warning: It is recommended to configure VLAN from config mode,
as VLAN database mode is being deprecated. Please consult user
documentation for configuring VTP/VLAN in config mode.
Rack1SW1(vlan)#vl
Rack1SW1(vlan)#vlan ?
<1-1005> ISL VLAN index
Rack1SW1(vlan)#exit
APPLY completed.
Exiting....
Rack1SW1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Rack1SW1(config)#vl
Rack1SW1(config)#vlan ?
WORD ISL VLAN IDs 1-4094
access-map Create vlan access-map or enter vlan access-map command mode
dot1q dot1q parameters
filter Apply a VLAN Map
internal internal VLAN
[edit] Tried to do this for a 3548XL i have (while the above output was from a 3560), and i found out that further on the 3500XL doesn't support extended VLANs:
"The 2900XL and 3500XL can use only VLANs in the range of 1 to 1001, and they do not support extended-range VLANs. If you upgrade the software of the switch, it does not bring an enhancement to support the configuration of extended-range VLANs."
http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080890613.shtml
BR,
Mohammed Mahmoud.