Managing Serviceguard 11th Edition, Version A.11.16, Second Printing June 2004

Understanding Serviceguard Software Components
How the Network Manager Works
Chapter 3 107
• Only port-based and IP subnet-based VLANs are supported.
Protocol-based VLAN will not be 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 in order to operate properly unless it is used as a standby of a
primary VLAN interface.
• VLAN interfaces over APA aggregates are not supported.
• Failover from physical LAN interface to VLAN interfaces or vice
versa is not supported due to restrictions of VLAN software.
• Using VLAN in a Wide Area Network cluster is not supported.
Enhanced Heartbeat Requirements
VLAN technology allows greater flexibility in network configurations in
the enterprise. In order to allow Serviceguard to be running on such
dynamic environments successfully while maintaining its reliability and
availability features simultaneously, the existing heartbeat rules must
continue to be applied with more restrictions when VLAN interfaces are
present in the cluster:
1. The existing minimum heartbeat requirements are unchanged, but
they will be checked against the physical networks instead of any
LAN interfaces, which may include VLAN interfaces, to avoid single
points of failure.
2. Heartbeats are still recommended on all networks, including VLANs.
3. If VLANs are not preferred for heartbeat networks, then heartbeats
are recommended for all remaining physical networks present in the
cluster ASCII file.