Planning and Implementing VLANs with HP-UX

In the scenario illustrated in Figure 6, the peer-to-peer communication can be between:

• Two HPVM guests virtual network interfaces through the shared virtual switch.

For example, guests A and C (virtual switch ports 1 and 3 respectively) can communicate

with each other over the RED VLAN.

• An HPVM guest virtual network interface and the physical network interface on the local

HPVM host, through the virtual switch.

For example, guests A and C can communicate to the host VLAN interface, lan5000, over

the RED VLAN. Similarly, guest B can communicate with the host VLAN interface lan5001

over the BLUE VLAN.

• An HPVM guest virtual network interface and a remote node through the virtual switch,

the associated network interface on the HPVM host and the physical network

For example, guest A can communicate with client X over the RED VLAN. Similarly, guest

B can communicate with client Y over the BLUE VLAN.

Also note that the second virtual network interface on guest C (port 4) is connected to a virtual

switch port that is not configured for VLANs. Thus, it cannot communicate with either guest A

(over the RED VLAN) or with guest B (over the BLUE VLAN). However, it still can communicate

with client Z that is also not a member of any VLAN.

The HPVM system administrator can enforce the required isolation policies by configuring

appropriate VLAN membership for virtual switch ports. The HPVM system administrator

configures virtual switch ports for the same VLAN if communication between corresponding

guest interfaces is desired. Note that the VLAN membership rules on the physical network are

now extended to HPVM guests by virtue of a VLAN-aware HPVM virtual switch.

Since the VLAN-aware virtual switch extends the VLAN-aware network domain, it follows that

VLAN configuration of the HPVM virtual switch(es) must be consistent with the VLAN

configuration of the physical network and vice-versa for proper operation and enforcement of

policies. For example, if an HPVM guest is to communicate with a remote host over a VLAN,

both the HPVM virtual switch port for the guest and the physical switch port that connect the

physical interface that backs the virtual switch must be configured for the same VLAN.

Future HP-UX VLAN Feature Additions

HP is investing in the following areas for improvements to the HP-UX VLAN product.

• Generic VLAN Reservation Protocol (GVRP) and Automatic Configuration: GVRP is an

IEEE protocol that allows a switch or an end station to advertise its VLAN membership to

its link partner. Using this mechanism, we could develop a mechanism for dynamically

assigning VLAN membership to end stations, so that you don’t need to manually assign

VLAN IDs to each NIC on an end station.

• Stack support for 802.1p/Cos/QoS (multi-queues): HP is investigating methods for

implementing an end-to-end Class of Service or Quality of Service solution by improving

on priority mechanisms in the network stack and NICs. An important component of this

solution will be the 802.1p mechanism.

• Application-based VLAN: Application-based VLANs provide the most flexible way for

configuring VLANs—VLAN-aware applications determine the membership of the traffic

they generate. This mechanism opens up a number of interesting possibilities. For example,

a set of stations may negotiate a dynamically created VLAN for the purpose of carrying on

a short-term audio or videoconference.

• HP-UX VLAN implementation will be a key value addition to many exciting new technologies

in the horizon, such as iSCSI, 10-Gigabit Ethernet, and IPv6.