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Cisco Systems IntelligentGigabit Ethernet Switch Modules for the IBMBladeCenter, Software Configuration Guide
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Chapter12 Configuring VLANs
Configuring Extended-Range VLANs
Default VLAN Configuration
See Table12-2 on page 12-7 for the default configuration for Ethernet VLANs. You can change only the
MTU size on extended-range VLANs; all other characteristics must remain at the default state.
Extended-Range VLAN Configuration Guidelines
Follow these guidelines when creating extended-range VLANs:
•To add an extended-range VLAN, you must use the vlan vlan-id global configuration command and
access config-vlan mode. You cannot add extended-range VLANs in VLAN database configuration
mode (accessed by entering the vlan database privileged EXEC command).
•VLAN IDs in the extended range are not saved in the VLAN database and are not recognized by
VTP.
•You cannot include extended-range VLANs in the pruning eligible range.
•The switch must be in VTP transparent mode when you create extended-range V LANs. If VTP mode
is server or client, an error message is generated, and the extended-range VLAN is rejected.
•You can set the VTP mode to transparent in global configuration mode or in VLAN database
configuration mode. See the “Disabling VTP (VTP Transparent Mode)” sectio n on page 13-11. You
should save this configuration to the startup configuration so that the switch will boot up in VTP
transparent mode. Otherwise, you will lose extended-range VLAN configuration if the switch resets.
•VLANs in the extended range are not supported by VQP. They cannot be configured by VMPS.
•STP is enabled by default on extended-range VLANs, but you can disable it by using the no
spanning-tree vlan vlan-id global configuration command. When the maximum number of
spanning-tree instances (64) are on the switch, spanning tree is disabled on any newly created
VLANs. If the number of VLANs on the switch exceeds the maximum number of 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
Chapter 10, “Configuring MSTP.”
Creating an Extended-Range VLAN
You create an extended-range VLAN in global configuration mode by entering the vlan global
configuration command with a VLAN ID from 1006 to 4094. This command accesses the config-vlan
mode. The extended-range VLAN has the default Ethernet VLAN cha racteristics (see Table 12-2), and
the MTU size is the only parameter you can change. See the description of the vlan global configuration
command in the command reference for defaults of all parameter s. If you enter an extended-range VLAN
ID when the switch is not in VTP transparent mode, an error message is generated when you exit from
config-vlan mode, and the extended-range VLAN is not created.
Extended-range VLANs are not saved in the VLAN database; they are saved in the switch running
configuration file. You can save the extended-range VLAN configuration in the switch startup
configuration file by using the copy running-config startup-config privileged EXEC command.