Serviceguard Network Manager: Inbound Failure Detection, March 2007

Figure 4. Single point of failure

Example 2: Another case of broken cascaded cable in a two-node cluster with only one NIC in each

cluster member and no standby where each NIC connects to a switch. The two switches are

connected by a cascading cable. These switches connect to routers and then to the client LAN. If the

cascading cable breaks, each NIC can send poll messages but neither can receive them. The

INONLY_OR_INOUT setting will identify both NICs as failed and the cluster health as fine. However,

the client network has lost connectivity to the cluster. In this situation, the default setting of INOUT is

used. See Figure 5 for an illustration of this example.

Figure 5. No standby NICs, cascaded cable broken

Example 3: Two nodes with a primary connection and no standby in a two-node cluster connected

with a primary connection, no standby and only one switch. Since there is only one network interface