Using HP-UX VLANs (September 2004)

What are HP-UX VLANs?

Types of VLANs Supported by HP-UX

Chapter 118

Types of VLANs Supported by HP-UX

HP-UX implements VLAN tagging using a mechanism called Virtual

Interfaces (VI). On each NIC port, you may conﬁgure multiple VIs,

each of which is associated with a unique VLAN ID and 802.1p priority

value. Each VI is assigned a virtual Physical Point of Attachment (PPA),

which you can use like any other PPA. For example, for conﬁguring

protocols, for attaching to an application, and so on. The type of VLAN

conﬁgured on an NIC port depends on how you create and conﬁgure VIs.

The types of HP-UX VLANs that you can create are as follows:

• NIC Port Based--A group of physical LAN card ports belong to the

same layer-2 broadcast domain. Each LAN card port transmits and

receives frames belonging to the VLAN associated with that port.

Members of the same port-based VLAN have the same VLAN ID. A

VLAN ID uniquely identiﬁes the VLAN to which a frame belongs.

You can create one VI on a given NIC port. All protocols and

applications use that VI’s virtual PPA to transmit data trafﬁc.

Therefore, all frames transmitted by that NIC port are tagged with

the VLAN ID conﬁgured for that VI.

• Protocol Based--Common protocols such as IP, IPX, AppleTalk,

Decnet, and NetBIOS are grouped into layer-2 broadcast domains.

You can create one VI per protocol. The protocol referred to here is a

Layer 3 protocol, or Network Layer protocol such as IPv4, IPv6, IPX,

and so on.

• IP Subnet Based--Each IP subnet has its own unique VLAN.

Trafﬁc from different subnets is logically separated from each other

as if each subnet were on a different LAN segment.

You can create one VI per IP subnet. In other words, you ﬁrst create

as many VIs as the number of subnets that you want to be conﬁgured

on a given NIC port, and then you conﬁgure IP addresses on their

Virtual PPAs.

HP-UX VLANs conform to IEEE speciﬁcations 802.1Q (for VLAN

tagging) and IEEE 802.1p (MAC-level frame prioritizing) to provide

end-to-end class of service (CoS).