Managing Serviceguard 13th Edition, February 2007

Understanding Serviceguard Software Components
How the Network Manager Works
Chapter 3108
Figure 3-17 Cluster After Local Network Switching
As the standby interface takes over, IP addresses will be switched to the
hardware path associated with the standby interface. The switch is
transparent at the TCP/IP level. All applications continue to run on their
original nodes. During this time, IP traffic on Node 1 will be delayed as
the transfer occurs. However, the TCP/IP connections will continue to be
maintained and applications will continue to run. Control of the
packages on Node 1 is not affected.
NOTE On Ethernet networks, Serviceguard supports local failover between
network interfaces configured with “Ethernet protocol” or between
network interfaces configured with “SNAP encapsulation within IEEE
802.3 protocol.” You cannot use both protocols on the same interface, nor
can you have a local failover between interfaces that are using different
protocols.
Another example of local switching is shown in Figure 3-18. In this case
a failure affecting segment 2 causes both nodes to switch to the LAN
cards attached to segment 1.