Managing Serviceguard 14th Edition, June 2007

Understanding Serviceguard Software Components
How the Network Manager Works
Chapter 3 109
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:
• A maximum of 30 network interfaces per node is supported. The
interfaces can be physical NIC ports, VLAN interfaces, APA
aggregates, or any combination of these.
• Local failover of VLANs must be onto the same link types. For
example, you must fail over from VLAN-over-Ethernet to
VLAN-over-Ethernet.
• The primary and standby VLANs must have same VLAN ID (or tag
ID).
• VLAN configurations are only supported on HP-UX 11i releases.
• Only port-based and IP-subnet-based VLANs are supported.
Protocol-based VLAN is not supported because Serviceguard does
not support any transport protocols other than TCP/IP.
• Each VLAN interface must be assigned an IP address in a unique
subnet, unless it is a standby for a primary VLAN interface.
• Failover from physical LAN interfaces to VLAN interfaces or vice
versa is not supported because of restrictions in VLAN software.
• Using VLAN in a Wide Area Network cluster is not supported.
• If CVM disk groups are used (on systems that support CVM; see
“About Veritas CFS and CVM from Symantec” on page 29), you must
not configure the Serviceguard heartbeat over VLAN interfaces.
Additional Heartbeat Requirements
VLAN technology allows great flexibility in network configuration. To
maintain Serviceguard’s reliability and availability in such an
environment, the heartbeat rules are tightened as follows when the
cluster is using VLANs: