PRIMECLUSTER Global Link Services Configuration and Administration Guide: Redundant Line Control Function 4.1 (for Solaris(TM) Operating System)

2.1.3.2 Switching function

Switching operation

Switching operation changes the status of an active NIC into "down" and "unplumb" state and then changes the status of standby NIC to "plumb" and "up" so that standby NIC can run as a new active device. At this point, the MAC address and IP addresses (physical IP and logical IP) are taken over and then an ARP request packet is broadcast, in which the MAC address/IP addresses of the local node are set as the source.
It is possible to choose either a logical IP address takeover function or a physical IP address takeover function as an IP takeover mode.
Both a logical IP address and a physical IP address are taking over at the time of logical IP address takeover function use. Only a physical IP address is taking over at the time of physical IP address takeover function use, without activating a logical IP address.
When using an IPv6 address, it is not possible to use a physical IP address takeover function.
Figure 2.16 shows an example of node internal switching.

When a failure is detected, a console message is output to the syslog file (/var/adm/messages). If a failure occurs when HUB-to-HUB communication monitoring is enabled, a console message is output to the syslog file (/var/adm/messages).

[Figure 2.16 Outline of switching operation performed when a failure occurs in NIC switching mode]

Failback operation

If a relevant NIC recovers after NIC switching occurs due to failure detection, you must switch it back manually via hanetnic change command.
Running this command makes recovered NIC to operate as an active NIC and recovers the system. In addition, if you setup a Standby Patrol Function, it automatically fails back the defective NIC without manually executing hanetnic change command. (For details regarding this operation, see "7.1 hanetconfig Command" and "7.9 hanetnic Command".) Furthermore, if in any case entire redundant NIC encounters failure, the monitoring process terminates. In such case, you must restart the process via hanetpoll off/on command after recovering the NIC. (For details on this command, see "7.7 hanetpoll Command")