Public Network FAQs

Which public network adapters does the Sun Cluster software support?

Currently, the Sun Cluster software supports Ethernet (10/100BASE-T and 1000BASE-SX Gb) public network adapters. Because new interfaces might be supported in the future, check with your Sun sales representative for the most current information.

What is the role of the MAC address in failover?

When a failover occurs, new Address Resolution Protocol (ARP) packets are generated and broadcast to the world. These ARP packets contain the new MAC address (of the new physical adapter to which the host failed over) and the old IP address. When another machine on the network receives one of these packets, it flushes the old MAC-IP mapping from its ARP cache and uses the new one.

Does the Sun Cluster software support setting local-mac-address?=true?

Yes. In fact, IP Network Multipathing requires that local-mac-address? must be set to true.

You can set local-mac-address with the eeprom command, at the OpenBoot PROM ok prompt in a SPARC based cluster. See the eeprom(1M) man page. You can also set the MAC address with the SCSI utility that you optionally run after the BIOS boots in an x86 based cluster.

How much delay can I expect when IP network multipathing performs a switchover between adapters?

The delay could be several minutes. The reason is because when an IP network multipathing switchover is performed, the operation sends a gratuitous ARP broadcast. However, you cannot be sure that the router between the client and the cluster uses the gratuitous ARP. So, until the ARP cache entry for this IP address on the router times out, the entry can use the stale MAC address.

How fast are failures of a network adapter detected?

The default failure detection time is 10 seconds. The algorithm tries to meet the failure detection time, but the actual time depends on the network load.