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

5.1.1.1.2 NIC switching mode

NIC switching mode has the following address takeover functions. Select a function to be used depending on your operation.

• Logical address takeover
  Using the logical address takeover function allows a LAN to have several virtual IP addresses. Ordinary communication will be done via a physical IP address, and a communication through GLS will be done via the virtual IP addresses.
  For the remote system device to make a connection, a physical IP address should be specified as the connection address. Then, the remote system device can directly connect to the active or standby node and manage each of the nodes regardless of the status transition of the userApplication.
  For this function, two IP addresses are assigned to one physical interface. To use a TCP/IP application that requires only one IP address to be specified, use the physical address takeover function I or II.
• Physical IP address takeover I
  Use the Physical IP address takeover function I for a GLS network and an ordinary network to exist in a same LAN, sharing an IP address allocated to a physical interface.
  This function allows a connection to be made for each of the active and standby nodes independently. However, IP address of the standby node changes according to the status transition of the userApplication. Thus, when clusters are switched, the TCP connection to the standby node is cleared. For the communication target device to make a connection again, the connection IP address must be changed.
• Physical IP address takeover II
  Use the Physical IP address takeover function II to use a LAN only for GLS networking. In this case, no connection can be made to the standby node because the LAN of the standby node is inactivated. Another LAN must be provided to make a connection.

Figure 5.3 shows the active standby configuration diagram of duplicated operation in NIC switching mode (logical IP address takeover function). The operation in this figure is as follows: On active node A, the logical interface (hme1:1) of the secondary interface (hme1) is assigned the takeover virtual IP address (IP-A) and activated. If switching occurs due to a failure, the takeover virtual interface (hme1:1) that has been assigned the takeover IP address (IP-A) is inactivated. Then, on standby node B, the logical interface (hme0:1) that has been assigned the takeover IP address (IP-A) on the already activated primary interface (hme0) is activated.

[Figure 5.3 Startup behavior of NIC switching mode (take over logical IP) ]

For taking over physical IP address I, activate the physical interface (hme1) for operating node and standby node when the Redundant Line Control function starts up. After the userApplication starts, it will activate the physical interface by allocating a takeover IP address to the physical interface on the operating node. At this time, a physical interface (hme1) over the standby node remains to be inactive.

Figure 5.4 shows a startup behavior of takeover physical IP address I

[Figure 5.4 Startup behavior of NIC switching mode (takeover physical IP address I)]

For taking over physical IP address II, it does not activate the physical interface (hme1) for both operating node and standby node when Redundant Line Control function starts up. Instead it allocates a takeover IP address to the physical interface (hme1) on the operating node and then it activates the physical interface. In this case, the physical interface (hme1) for standby node remains inactive.

Figure 5.5 shows a startup behavior of the takeover physical IP address II

[Figure 5.5 Startup behavior of NIC switching mode (takeover physical IP address II)]