Specifications

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Catalyst 2970 Switch Software Configuration Guide
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Chapter 11 Configuring VLANs
Configuring Normal-Range VLANs
For more detailed definitions of the modes and their functions, see Table 11-4 on page 11-16.
When a port belongs to a VLAN, the switch learns and manages the addresses associated with the port
on a per-VLAN basis. For more information, see the “Managing the MAC Address Table” section on
page 6-22.
Configuring Normal-Range VLANs
Normal-range VLANs are VLANs with VLAN IDs 1 to 1005. If the switch is in VTP server or
transparent mode, you can add, modify or remove configurations for VLANs 2 to 1001 in the VLAN
database. (VLAN IDs 1 and 1002 to 1005 are automatically created and cannot be removed.)
Note When the switch is in VTP transparent mode, you can also create extended-range VLANs (VLANs with
IDs from 1006 to 4094), but these VLANs are not saved in the VLAN database. See the “Configuring
Extended-Range VLANs” section on page 11-12.
Configurations for VLAN IDs 1 to 1005 are written to the file vlan.dat (VLAN database), and you can
display them by entering the show vlan privileged EXEC command. The vlan.dat file is stored in Flash
memory.
Caution You can cause inconsistency in the VLAN database if you attempt to manually delete the vlan.dat file.
If you want to modify the VLAN configuration, use the commands described in these sections and in the
command reference for this release. To change the VTP configuration, see Chapter 12, “Configuring
VTP.”
You use the interface configuration mode to define the port membership mode and to add and remove
ports from VLANs. The results of these commands are written to the running-configuration file, and you
can display the file by entering the show running-config privileged EXEC command.
Dynamic access A dynamic-access port can belong to one VLAN (VLAN
ID 1 to 4094) and is dynamically assigned by a VMPS. The
VMPS can be a Catalyst 5000 or Catalyst 6000 series
switch, for example, but never a Catalyst 2970 switch. The
Catalyst 2970 switch is a VMPS client.
You can have dynamic-access ports and trunk ports on the
same switch, but you must connect the dynamic-access
port to an end station or hub and not to another switch.
For configuration information, see the “Configuring
Dynamic-Access Ports on VMPS Clients” section on
page 11-29.
VTP is required.
Configure the VMPS and the client with
the same VTP domain name.
To participate in VTP, there must be at least
one trunk port on the switch connected to a
trunk port of a second switch.
Voice VLAN A voice VLAN port is an access port attached to a Cisco
IP Phone, configured to use one VLAN for voice traffic
and another VLAN for data traffic from a device attached
to the phone. For more information about voice VLAN
ports, see Chapter 13, “Configuring Voice VLAN.”
VTP is not required; it has no affect on
voice VLAN.
Table 11-1 Port Membership Modes (continued)
Membership Mode VLAN Membership Characteristics VTP Characteristics