Cisco Nexus 5000 Series Switch CLI Software Configuration Guide, NX-OS 4.0(1a)N1 (OL-16597-01, January 2009)

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6-3
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
OL-16597-01
Chapter 6 Configuring VLANs
Information About VLANs
Table 6-1 describes the details of the VLAN ranges.
Note VLANs 3968 to 4047 and 4094 are reserved for internal use; these VLANs cannot be changed or used.
Cisco NX-OS allocates a group of 80 VLAN numbers for those features, such as multicast and
diagnostics, that need to use internal VLANs for their operation. By default, the system allocates VLANs
numbered 3968 to 4047 for internal use. VLAN 4094 is also reserved for internal use by the switch.
You cannot use, modify, or delete any of the VLANs in the reserved group. You can display the VLANs
that are allocated internally and their associated use.
Creating, Deleting, and Modifying VLANs
VLANs are numbered from 1 to 4094. All configured ports belong to the default VLAN when you first
bring up the switch. The default VLAN (VLAN1) uses only default values, and you cannot create, delete,
or suspend activity in the default VLAN.
You create a VLAN by assigning a number to it; you can delete VLANs as well as moving them from
the active operational state to the suspended operational state. If you attempt to create a VLAN with an
existing VLAN ID, the switch goes into the VLAN submode but does not create the same VLAN again.
Newly created VLANs remain unused until ports are assigned to the specific VLAN. All the ports are
assigned to VLAN1 by default.
Depending on the range of the VLAN, you can configure the following parameters for VLANs (except
the default VLAN):
• VLAN name
• Shutdown or not shutdown
When you delete a specified VLAN, the ports associated to that VLAN are shut down and no traffic
flows. However, the system retains all the VLAN-to-port mapping for that VLAN, and when you
reenable, or recreate, the specified VLAN, the system automatically reinstates all the original ports to
that VLAN.
Table 6-1 VLAN Ranges
VLANs
Numbers Range Usage
1 Normal Cisco default. You can use this VLAN, but you cannot modify or
delete it.
2—1005 Normal You can create, use, modify, and delete these VLANs.
1006—4094 Extended You can create, name, and use these VLANs. You cannot change the
following parameters:
• State is always active.
• VLAN is always enabled. You cannot shut down these VLANs.
3968—4047
and 4094
Internally
allocated
These 80 VLANs, plus VLAN 4094, are allocated for internal use.
You cannot create, delete, or modify any VLANs within the block
reserved for internal use.