Managing Serviceguard 12th Edition, March 2006

Understanding Serviceguard Software Components
How the Network Manager Works
Chapter 3 111
interfaces to form their own subnets. Please refer to the document Using
HP-UX VLAN (T1453-90001) for more details on how to configure VLAN
interfaces.
Support for HP-UX VLAN
The support of VLAN is similar to other link technologies. VLAN
interfaces can be used as heartbeat as well as data networks in the
cluster. The Network Manager will monitor the health of VLAN
interfaces configured in the cluster, and perform local and remote
failover of VLAN interfaces when failure is detected. The failure of
VLAN interfaces typically occurs when the physical NIC port, upon
which they are created, has failed.
Configuration Restrictions
HP-UX allows up to 1024 VLANs to be created from a physical NIC port.
Obviously, a large pool of system resources is required to accommodate
such a configuration. With the availability of VLAN technology,
Serviceguard may face potential performance degradation, high CPU
utilization and memory shortage issues if there is a large number of
network interfaces configured in each cluster node. To provide enough
flexibility in VLAN networking, Serviceguard solutions should adhere to
the following VLAN and general network configuration requirements:
• A maximum of 30 network interfaces per node is supported in the
cluster ASCII file. The interfaces can be physical NIC ports, VLAN
interfaces, APA aggregates, or any combination of these.
• The physical LAN interfaces, upon which the VLAN interfaces are
created, should be configured in the ASCII file along with the VLAN
interfaces to meet Serviceguard heartbeat requirements.
• A maximum of 14 VLAN interfaces per physical NIC port is
supported if there are at least two NIC ports configured with VLAN
in a cluster node. This limit can be increased to 28 VLAN interfaces
if the physical NIC port is the only NIC port configured with VLAN.
These restrictions are bound by the 30 network interfaces per node
limit. One example to show this configuration is a cluster node with 2
single-ported NIC cards, both of which are configured as heartbeat
networks. Then each can have up to 14 VLAN interfaces per NIC
card totaling 30 network interfaces per node.
• Local failover of VLANs must be on same link types. The primary
and standby VLANs must have same vlan id (or tag id).