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Catalyst 3750 Switch Software Configuration Guide
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Chapter 13 Configuring VLANs
Configuring Extended-Range VLANs
• Although the switch stack supports a total of 1005 (normal-range and extended-range) VLANs, the
number of routed ports, SVIs, and other configured features affects the use of the switch hardware.
If you try to create an extended-range VLAN and there are not enough hardware resources available,
an error message is generated, and the extended-range VLAN is rejected.
• In a switch stack, the whole stack uses the same running configuration and saved configuration, and
extended-range VLAN information is shared across the stack.
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 characteristics (see Table 13-2) and
the MTU size and RSPAN configuration are the only parameters you can change. Refer to the description
of the vlan global configuration command in the command reference for defaults of all parameters. 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.
Note Before you create an extended-range VLAN, you can verify that the VLAN ID is not used internally by
entering the show vlan internal usage privileged EXEC command. If the VLAN ID is used internally
and you want to free it up, go to the“Creating an Extended-Range VLAN with an Internal VLAN ID”
section on page 13-15 before creating the extended-range VLAN.
Beginning in privileged EXEC mode, follow these steps to create an extended-range VLAN:
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
vtp mode transparent Configure the switch for VTP transparent mode, disabling VTP.
Step 3
vlan vlan-id Enter an extended-range VLAN ID and enter config-vlan mode. The
range is 1006 to 4094.
Step 4
mtu mtu-size (Optional) Modify the VLAN by changing the MTU size.
Note Although all VLAN commands appear in the CLI help in
config-vlan mode, only the mtu mtu-size and remote-span
commands are supported for extended-range VLANs.
Step 5
remote-span (Optional) Configure the VLAN as the RSPAN VLAN. See the
“Configuring a VLAN as an RSPAN VLAN” section on page 27-18.
Step 6
end Return to privileged EXEC mode.
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