Managing Serviceguard Fifteenth Edition, reprinted May 2008

Understanding Serviceguard Software Components
How the Network Manager Works
Chapter 3110
For information about implementing APA with Serviceguard, see the
latest version of the HP Auto Port Aggregation (APA) Support Guide and
other APA documents posted at docs.hp.com in the IO Cards and
Networking Software collection.
VLAN Configurations
Virtual LAN configuration using HP-UX VLAN software is supported in
Serviceguard clusters.
What is VLAN?
Virtual LAN (or VLAN) is a technology that allows logical grouping of
network nodes, regardless of their physical locations.
VLAN can be used to divide a physical LAN into multiple logical LAN
segments or broadcast domains, helping to reduce broadcast traffic,
increase network performance and security, and improve manageability.
Multiple VLAN interfaces, each with its own IP address, can be
configured from a physical LAN interface; these VLAN interfaces appear
to applications as ordinary network interfaces (NICs). See Using HP-UX
VLAN (5991-0617) for more information on configuring VLAN interfaces.
Support for HP-UX VLAN
VLAN interfaces can be used as heartbeat as well as data networks in
the cluster. The Network Manager monitors the health of VLAN
interfaces configured in the cluster, and performs local and remote
failover of VLAN interfaces when failure is detected. Failure of a VLAN
interface is typically the result of the failure of the underlying physical
NIC port or aggregated (APA) ports.
Configuration Restrictions
HP-UX allows up to 1024 VLANs to be created from a physical NIC port.
A large pool of system resources is required to accommodate such a
configuration; Serviceguard could suffer performance degradation if
many network interfaces are configured in each cluster node. To prevent
this and other problems, Serviceguard imposes the following restrictions: