Using SNAplus2 in a High Availability Environment

Using SNAplus2 with MC/ServiceGuard

To protect against a failure of a server’s LAN adapter, you can configure a standby LAN adapter for the server. You can configure ServiceGuard to assign the primary LAN adapter’s IP address to the standby LAN adapter in the event of a failure. This way, TCP/IP connections from the client system to the server system would be maintained during the switch.

SNA LAN Connections

Another way SNAplus2 uses LANs is when the SNAplus2 server is connected to the remote SNA system via a LAN.

Figure D-8SNAplus2 Server connected to remote system via LAN

HP 9000

Server

Token

Ring LAN

3xxx

Communications

Controller

IBM

Host

For this type of communication, SNAplus2 communicates with the LAN driver using a Streams DLPI interface. Since ServiceGuard only supports local LAN failover for IP network traffic, SNAplus2 will not be able to take advantage of local LAN failover or floating IP addresses in this case. If an SNA LAN adapter fails, SNA sessions will be disconnected and the normal package failure recovery will take place.

Appendix D

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