10-3
Software Configuration Guide—Release 12.2(25)SG
OL-7659-03
Chapter10 Understanding and Conf iguring VLANs, VTP, and VMPS
VLANs
VLAN Configuration Guidelines and Restrictions
Follow these guidelines and restrictions when creating and m odifying VLANs in your network:
•Before creating a VLAN, put the Catalyst4500 series switch in VTP server mode or VTP
transparent mode. If the Catalyst4500 series switch is a VTP server, you must define a VTP domain.
For information on configuring VTP, see Chapter 27, “Understanding and Configuring VTP.”
•The Cisco IOS end command is not supported in VLAN database mode.
•You cannot use Ctrl-Z to exit VLAN database mode.

VLAN Ranges

Note You must enable the extended system ID to use 4094 VLANs. See the “Understanding the Bridge ID”
section on page 13-2.
With Cisco IOS Release 12.2(25)EWA and later, Catalyst4500 se ries switches support 4096 VLANs in
compliance with the IEEE 802.1Q standard. These VLANs are organized into three rang es: reserved,
normal, and extended.
Some of these VLANs are propagated to other switches in the network when you use the VLAN
Trunking Protocol (VTP). The extended-range VLANs are not propagated, so you must configure
extended-range VLANs manually on each network device.
Table10-1 describes the uses for VLAN ranges.
Table10-1 VLAN Ranges
VLANs Range Usage
Propagated
by VTP
0, 4095 Reserved For system use only. You cannot see or use these VLANs. —
1 Normal Cisco default. You can use this VLAN but you cannot delete it. Yes
2–1001 Normal Used for Ethernet VLANs; you can create, use, and delete these VLANs. Yes
1002–1005 N ormal Cisco defaults for FDDI and Token Ring. You cannot delete VLANs 1002–1005. Yes
1006–4094 E xtended For Ethernet VLANs only. When configuring extended-range VLANs, note the
following:
•Layer 3 ports and some software features require internal VLANs. Internal
VLANs are allocated from 1006 and up. You cannot use a VLAN that has been
allocated for such use. To display the VLANs used internally, enter the show
vlan internal usage command.
•Switches running Catalyst product family software do not support
configuration of VLANs 1006–1024. If you configure VLANs 1006–1024,
ensure that the VLANs do not extend to any switches running Catalyst produc t
family software.
•You must enable the extended system ID to use extended range VLANs. See
the “Enabling the Extended System ID” section on page 13-8.
No