Trunk Group Ports And Vlan Membership; Summary Of Vlan Configuration Rules; Routing Between Vlans - HP ProCurve 9304M Installation And Configuration Manual

provide a private, dedicated Ethernet connection for an individual client to transparently reach its sub-net across
multiple networks.
For an application example and configuration information, see "Configuring Super Aggregated VLANs" on
page 11-42.

Trunk Group Ports and VLAN Membership

A trunk group is a set of physical ports that are configured to act as a single physical interface. Each trunk group's
port configuration is based on the configuration of the lead port, which is the lowest numbered port in the group.
If you add a trunk group's lead port to a VLAN, all of the ports in the trunk group become members of that VLAN.

Summary of VLAN Configuration Rules

A hierarchy of VLANs exists between the Layer 2 and Layer 3 protocol-based VLANs:
• Port-based VLANs are at the lowest level of the hierarchy.
• Layer 3 protocol-based VLANs, IP, IPv6, IPX, AppleTalk, Decnet, and NetBIOS are at the middle level of the
hierarchy.
• IP sub-net, IPX network, and AppleTalk cable VLANs are at the top of the hierarchy.
NOTE: You cannot have a protocol-based VLAN and a sub-net or network VLAN of the same protocol type in the
same port-based VLAN. For example, you can have an IPX protocol VLAN and IP sub-net VLAN in the same
port-based VLAN, but you cannot have an IP protocol VLAN and an IP sub-net VLAN in the same port-based
VLAN, nor can you have an IPX protocol VLAN and an IPX network VLAN in the same port-based VLAN.
As an HP device receives packets, the VLAN classification starts from the highest level VLAN first. Therefore, if
an interface is configured as a member of both a port-based VLAN and an IP protocol VLAN, IP packets coming
into the interface are classified as members of the IP protocol VLAN because that VLAN is higher in the VLAN
hierarchy.
Multiple VLAN Membership Rules
• A port can belong to multiple, unique, overlapping Layer 3 protocol-based VLANs without VLAN tagging.
• A port can belong to multiple, overlapping Layer 2 port-based VLANs only if the port is a tagged port. Packets
sent out of a tagged port use an 802.1q-tagged frame.
• When both port and protocol-based VLANs are configured on a given device, all protocol VLANs must be
strictly contained within a port-based VLAN. A protocol VLAN cannot include ports from multiple port-based
VLANs. This rule is required to ensure that port-based VLANs remain loop-free Layer 2 broadcast domains.
• IP protocol VLANs and IP sub-net VLANs cannot operate concurrently on the system or within the same port-
based VLAN.
• IPX protocol VLANs and IPX network VLANs cannot operate concurrently on the system or within the same
port-based VLAN.
• If you first configure IP and IPX protocol VLANs before deciding to partition the network by IP sub-net and IPX
network VLANs, then you need to delete those VLANs before creating the IP sub-net and IPX network
VLANs.
• Removing a configured port-based VLAN from a Hewlett-Packard Routing Switch automatically removes any
protocol-based VLAN, IP sub-net VLAN, AppleTalk cable VLAN, or IPX network VLAN, or any Virtual Ethernet
router interfaces defined within the Port-based VLAN.

Routing Between VLANs

HP Routing Switches can locally route IP, IPX, and Appletalk between VLANs defined within a single router. All
other routable protocols or protocol VLANs (for example, DecNet) must be routed by another external router
capable of routing the protocol.
Configuring Virtual LANs (VLANs)
11 - 11