Managing Serviceguard 14th Edition, June 2007

Understanding Serviceguard Software Components
How the Network Manager Works
Chapter 3102
Within the Ethernet family, local switching is supported in the following
configurations:
• 1000Base-SX and 1000Base-T
• 1000Base-T or 1000BaseSX and 100Base-T
On HP-UX 11i, however, Jumbo Frames can only be used when the
1000Base-T or 1000Base-SX cards are configured. The 100Base-T and
10Base-T do not support Jumbo Frames. Additionally, network interface
cards running 1000Base-T or 1000Base-SX cannot do local failover to
10BaseT.
During the transfer, IP packets will be lost, but TCP (Transmission
Control Protocol) will retransmit the packets. In the case of UDP (User
Datagram Protocol), the packets will not be retransmitted automatically
by the protocol. However, since UDP is an unreliable service, UDP
applications should be prepared to handle the case of lost network
packets and recover appropriately. Note that a local switchover is
supported only between two LANs of the same type. For example, a local
switchover between Ethernet and IPoIB interfaces is not supported, but
a local switchover between 10BT Ethernet and 100BT Ethernet is
supported.
Figure 3-16 shows two nodes connected in one bridged net. LAN
segments 1 and 2 are connected by a hub.