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Catalyst 3750 SwitchSoftware Configuration Guide
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Chapter13 Configuring VLANs
Configuring Normal-Range VLANs
For more detailed definitions of access and trunk modes and their functions, see Table13-4 on
page 13-17.
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 7-19.
Configuring Normal-Range VLANs
Normal-range VLANs are VLANs with VLAN IDs 1 to 1005. If the switch is in VTP server or
VTP 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.)
In VTP versions 1 and 2, the switch must be in VTP transparent mode when you create extended-range
VLANs (VLANs with IDs from 1006 to 4094), but these VLANs are not saved in the VLAN database.
VTP version 3 supports extended-range VLANs in VTP server and transparent mode. See the
“Configuring Extended-Range VLANs” section on page 13-11.
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 on the stack master. Stack members have a vlan.dat file that is consistent with the stack master.
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 15, “Configuring Voice VLAN.
VTP is not required; it has no effect on a
voice VLAN.
Private VLAN A private VLAN port is a host or promiscuous port
that belongs to a private VLAN primary or secondary
VLAN.
For information about private VLANs, see
Chapter 16, “Configuring Private VLANs.”
In VTP versions 1 and 2, the switch must be
in VTP transparent mode when you
configure private VLANs. When private
VLANs are configured on the switch, do not
change VTP mode from transparent to client
or server mode. VTP version 3 supports
private VLANs in any mode.
Tunnel
(dot1q-tunnel)
Tunnel ports are used for IEEE 802.1Q tunneling to
maintain customer VLAN integrity across a
service-provider network. You configure a tunnel
port on an edge switch in the service-provider
network and connect it to an IEEE 802.1Q trunk port
on a customer interface, creating an asymetric link. A
tunnel port belongs to a single VLAN that is
dedicated to tunneling.
For more information about tunnel ports, see
Chapter 17, “Configuring IEEE 802.1Q and Layer 2
Protocol Tunneling.”
VTP is not required. You manually assign
the tunnel port to a VLAN by using the
switchport access vlan interface
configuration command.
Table13-1 Port Membership Modes and Characteristics
Membership Mode VLAN Membership Characteristics VTP Characteristics