Managing Serviceguard 13th Edition, February 2007

Understanding Serviceguard Software Components
How the Network Manager Works
Chapter 3 113
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 can failover from VLAN-over-Ethernet to
VLAN-over-Ethernet, or VLAN-over-FDDI to VLAN-over-FDDI, but
not VLAN-over-Ethernet to VLAN-over-FDDI or vice versa.
• 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” on page 27), you must not configure
the Serviceguard heartbeat over VLAN interfaces.