Cisco Systems 3130 User Manual
10-2
Cisco Catalyst Blade Switch 3130 for Dell Software Configuration Guide
OL-13270-01
Chapter 10 Configuring Interface Characteristics
Understanding Interface Types
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Port-Based VLANs
A VLAN is a switched network that is logically segmented by function, team, or application, without
regard to the physical location of the users. For more information about VLANs, see
regard to the physical location of the users. For more information about VLANs, see
Packets received on a port are forwarded only to ports that belong to the same
VLAN as the receiving port. Network devices in different VLANs cannot communicate with one another
without a Layer 3 device to route traffic between the VLANs.
without a Layer 3 device to route traffic between the VLANs.
VLAN partitions provide hard firewalls for traffic in the VLAN, and each VLAN has its own MAC
address table. A VLAN comes into existence when a local port is configured to be associated with the
VLAN, when the VLAN Trunking Protocol (VTP) learns of its existence from a neighbor on a trunk, or
when a user creates a VLAN. VLANs can be formed with ports across the stack.
address table. A VLAN comes into existence when a local port is configured to be associated with the
VLAN, when the VLAN Trunking Protocol (VTP) learns of its existence from a neighbor on a trunk, or
when a user creates a VLAN. VLANs can be formed with ports across the stack.
To configure normal-range VLANs (VLAN IDs 1 to 1005), use the vlan vlan-id global configuration
command to enter config-vlan mode or the vlan database privileged EXEC command to enter VLAN
database configuration mode. The VLAN configurations for VLAN IDs 1 to 1005 are saved in the VLAN
database. In a switch stack, the VLAN database is downloaded to all switches in a stack, and all switches
in the stack build the same VLAN database.
command to enter config-vlan mode or the vlan database privileged EXEC command to enter VLAN
database configuration mode. The VLAN configurations for VLAN IDs 1 to 1005 are saved in the VLAN
database. In a switch stack, the VLAN database is downloaded to all switches in a stack, and all switches
in the stack build the same VLAN database.
To configure extended-range VLANs (VLAN IDs 1006 to 4094), you must use config-vlan mode with
VTP mode set to transparent. Extended-range VLANs are not added to the VLAN database. When VTP
mode is transparent, the VTP and VLAN configuration is saved in the switch running configuration, and
you can save it in the switch startup configuration file by entering the copy running-config
startup-config privileged EXEC command. In a switch stack, the running configuration and the saved
configuration are the same for all switches in a stack.
VTP mode set to transparent. Extended-range VLANs are not added to the VLAN database. When VTP
mode is transparent, the VTP and VLAN configuration is saved in the switch running configuration, and
you can save it in the switch startup configuration file by entering the copy running-config
startup-config privileged EXEC command. In a switch stack, the running configuration and the saved
configuration are the same for all switches in a stack.
Add ports to a VLAN by using the switchport interface configuration commands:
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Identify the interface.
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For a trunk port, set trunk characteristics, and, if desired, define the VLANs to which it can belong.
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For an access port, set and define the VLAN to which it belongs.
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For a tunnel port, set and define the VLAN ID for the customer-specific VLAN tag. See
Switch Ports
Switch ports are Layer 2-only interfaces associated with a physical port. Switch ports belong to one or
more VLANs. A switch port can be an access port, a trunk port, or a tunnel port. You can configure a port
as an access port or trunk port or let the Dynamic Trunking Protocol (DTP) operate on a per-port basis
to set the switchport mode by negotiating with the port on the other end of the link. You must manually
configure tunnel ports as part of an asymmetric link connected to an IEEE 802.1Q trunk port. Switch
ports are used for managing the physical interface and associated Layer 2 protocols and do not handle
routing or bridging.
more VLANs. A switch port can be an access port, a trunk port, or a tunnel port. You can configure a port
as an access port or trunk port or let the Dynamic Trunking Protocol (DTP) operate on a per-port basis
to set the switchport mode by negotiating with the port on the other end of the link. You must manually
configure tunnel ports as part of an asymmetric link connected to an IEEE 802.1Q trunk port. Switch
ports are used for managing the physical interface and associated Layer 2 protocols and do not handle
routing or bridging.
Configure switch ports by using the switchport interface configuration commands. Use the switchport
command with no keywords to put an interface that is in Layer 3 mode into Layer 2 mode.
command with no keywords to put an interface that is in Layer 3 mode into Layer 2 mode.