Planning and Implementing VLANs with HP-UX

addresses to them. Then configure the same VLANs on the switch port, marking them
“tagged.” One (and only one) untagged VLAN can be configured on a switch port.
— If a workstation needs to belong to more than one VLAN and supports tagging, follow
the same steps as outlined for the server configuration.
Using HP-UX VLANs with HP Auto Port Aggregation (APA)
HP APA is a software product that creates link aggregates, often called trunks, which provide
a logical grouping of two or more physical ports into a single fat pipe. This port arrangement
provides more data bandwidth than would otherwise be available. HP APA also allows users
to create failover groups, which is a link aggregate in LAN_MONITOR configuration mode, of
two or more physical ports. A failover group provides redundancy of network links within the
group.
The HP APA interfaces can be in any of the modes, including:
– Manual trunk
– IEEE 802.1d Link Aggregation Control Protocol
– Cisco's Port Aggregation Protocol
– Lan Monitor failover groups
NOTE: The industry leading performance and scalability of the HP APA product are documented
in the HP APA Performance and Scalability White Paper, located at:
http://docs.hp.com/en/7662/new-apa-white-paper.pdf
HP-UX VLAN interfaces are also now configurable over HP APA interfaces. VLAN over APA
is supported on HP-UX 11i Version 2 (11.23) with the latest requisite updates and patches, and
is supported on HP-UX 11i Version 3 (11.31) as shipped, with no additional patches required.
VLAN over APA server technology offers several benefits. Using VLANs over link aggregates
and failover groups:
• Enables network I/O consolidation and higher bandwidth, through efficient usage of multiple
links under a single logical APA interface.
• Improves reliability, because the VLANs continue to carry traffic in case the active link
failed.
• Provides flexible configuration options for applications, through multiple VLAN interfaces
created over highly available APA interfaces. Multiple VLAN interfaces can be configured
for separate IP subnets used by different applications. Applications using use-dedicated
links prior to consolidation can now use VLAN interfaces created over the highly available
HP APA aggregate or LAN Monitor failover group.
Thus, VLAN over APA enables resilient network I/O consolidation on servers with a limited
number of slots for network I/O.
Figure 5 illustrates the value proposition of traffic isolation and higher bandwidth realized with
VLAN over APA technology. In the figure, each workgroup traffic is isolated from others, but
still run over the same set of NICs. The NICs are aggregated for high bandwidth with added
resilience to network failures using HP APA LAN Monitor technology
5
.
5. LAN Monitor uses polling packets to monitor the connectivity among the links in the failover group. These packets
are always sent untagged. The switch must be configured to allow for the forwarding of these untagged polling
packets.
VLANs on HP-UX 15