Normal-Range Vlan Configuration Guidelines; Vlan Configuration Mode Options - Cisco WS-C3560-48PS-S Software Configuration Manual

Configuring Normal-Range VLANs

Normal-Range VLAN Configuration Guidelines

Follow these guidelines when creating and modifying normal-range VLANs in your network:
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VLAN Configuration Mode Options

You can configure normal-range VLANs (with VLAN IDs 1 to 1005) by using these two configuration
modes:
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Catalyst 3560 Switch Software Configuration Guide
12-6
The switch supports 1005 VLANs in VTP client, server, and transparent modes.
Normal-range VLANs are identified with a number between 1 and 1001. VLAN numbers 1002
through 1005 are reserved for Token Ring and FDDI VLANs.
VLAN configuration for VLANs 1 to 1005 are always saved in the VLAN database. If VTP mode
is transparent, VTP and VLAN configuration is also saved in the switch running configuration file.
The switch also supports VLAN IDs 1006 through 4094 in VTP transparent mode (VTP disabled).
These are extended-range VLANs and configuration options are limited. Extended-range VLANs
are not saved in the VLAN database. See the
page 12-12.
Before you can create a VLAN, the switch must be in VTP server mode or VTP transparent mode.
If the switch is a VTP server, you must define a VTP domain or VTP will not function.
The switch does not support Token Ring or FDDI media. The switch does not forward FDDI,
FDDI-Net, TrCRF, or TrBRF traffic, but it does propagate the VLAN configuration through VTP.
The switch supports 128 spanning-tree instances. If a switch has more active VLANs than supported
spanning-tree instances, spanning tree can be enabled on 128 VLANs and is disabled on the
remaining VLANs. If you have already used all available spanning-tree instances on a switch,
adding another VLAN anywhere in the VTP domain creates a VLAN on that switch that is not
running spanning-tree. If you have the default allowed list on the trunk ports of that switch (which
is to allow all VLANs), the new VLAN is carried on all trunk ports. Depending on the topology of
the network, this could create a loop in the new VLAN that would not be broken, particularly if there
are several adjacent switches that all have run out of spanning-tree instances. You can prevent this
possibility by setting allowed lists on the trunk ports of switches that have used up their allocation
of spanning-tree instances.
If the number of VLANs on the switch exceeds the number of supported spanning tree instances, we
recommend that you configure the IEEE 802.1S Multiple STP (MSTP) on your switch to map
multiple VLANs to a single STP instance. For more information about MSTP, see
"Configuring MSTP."
VLAN Configuration in config-vlan Mode, page 12-7
You access config-vlan mode by entering the vlan vlan-id global configuration command.
VLAN Configuration in VLAN Database Configuration Mode, page 12-7
You access VLAN database configuration mode by entering the vlan database privileged EXEC
command.
Chapter 12
"Configuring Extended-Range VLANs" section on
Configuring VLANs
Chapter 16,
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