Ports, Vlans, And L3 Interfaces; Port-Based Vlans; Explicit And Implicit Vlans - HP procurve 8100fl series Management And Configuration Manual

VLAN Configuration
Overview
The 8100fl switch uses VLANs to achieve this behavior. This means that a Layer
3 subnet (that is, an IP subnet) is mapped to a VLAN. A given subnet maps to
exactly one and only one VLAN. With this definition, the terms VLAN and
subnet are almost interchangeable.
To configure a ProCurve 8100fl switch as a combined switch and router, the
administrator must create VLANs whenever multiple ports of the switch are
to belong to a particular VLAN/subnet. Then the VLAN must be bound to an
L3 (IP) interface so that the switch knows which VLAN maps to which IP
subnet.

Ports, VLANs, and L3 Interfaces

The term port refers to a physical connector on the switch, such as a
GigabitEthernet port. Each port must belong to at least one VLAN. When the
8100fl switch is unconfigured, each port belongs to a VLAN called the "default
VLAN." By creating VLANs and adding ports to the created VLANs, the ports
are moved from the default VLAN to the newly created VLANs.
Unlike traditional routers, the 8100fl switch has the concept of logical inter­
faces rather than physical interfaces. An L3 interface is a logical entity created
by the administrator. It can contain more than one physical port. When an L3
interface contains exactly one physical port, it is equivalent to an interface on
a traditional router. When an L3 interface contains several ports, it is equiva­
lent to an interface of a traditional router which is connected to a Layer 2
device such as a switch or bridge.

Port-based VLANs

Ports of L2 devices (switches, bridges) are assigned to VLANs. Any traffic
received by a port is classified as belonging to the VLAN to which the port
belongs. For example, if ports 1, 2, and 3 belong to the VLAN named
"Marketing", then a broadcast frame received by port 1 is transmitted on ports
2 and 3. It is not transmitted on any other port.

Explicit and Implicit VLANs

As mentioned earlier, VLANs can either be created explicitly by the adminis­
trator (explicit VLANs) or are created implicitly by the switch when L3
interfaces are created (implicit VLANs).
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