HP T1453-90001 Planning HP-UX VLANs, Communication between Vlans Requires an External Router

Overview of Installation and Configuration

Planning HP-UX VLANs

Planning HP-UX VLANs

The following requirements must be satisfied before setting up VLANs in an HP-UX network:

•In order for both end stations of a VLAN to communicate, both the end-station LAN cards and the switch ports that are connected to those LAN cards on a point-to-point link need to be VLAN-tag-aware.

•For VLANs to communicate with each other, an external VLAN-aware switch or router is required (Figure 2-1). However, it is not possible to extend a single vlan across a router.

•If a hub is connected to a network of VLANs, every port on the hub must belong to the same VLAN. Hubs do not have the ability to provide VLANs to individual ports.

VLAN awareness does not provide any benefit in a shared LAN environment (using hubs or repeaters). In these shared LAN environments, all stations see all traffic whether it is VLAN tagged or not.

Figure 2-1 Communication between VLANS Requires an External Router

LAN Card with Two

Port-Based

VLANs Configured

Port A2

Red VLAN

External	Port A1
Router	Port A3

Green VLAN

Port A4

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