100 Mbps full duplex


Each private heartbeat on a host should go to independent private separate physical networks, and each node in the cluster should have exactly one NIC connected to each of the private networks.  

Typically, each node connects the same nic names together.

The NIC's can not be part of any trunking, tunneling, etherchannel, Agregate port (802.3ad) or "multi" path/nic schemes, etc.  As the NIC"s are not plumbed up and should not be configured for any routable protocols, the nodes should not route or tunnel any LLT traffic from one NIC to another. 
If additional reliablilty or thruput is desired, setup more (up to 4) private heartbeat networks. 

For RAC, all NIC's must be configured to the same speed and duplex mode, and no lowpri, UDP, or public heartbeats used. RAC heartbeat networks should not be shared with any other clusters, applications, etc.  The only hosts connected to the networks should all be from the same cluster. 

There should be no connections or overlaps between the private heartbeat networks.  

In LLT, link0 refers to the network attached to the link0 NIC, etc.  For link0 and link1 to hear the same MAC, either there are two NIC's with the same MAC, or the NIC with the Mac is attached to both networks.  

Much of how well the cluster functions depends on the networks being independent. 

Cust's /etc/llttab's use /dev/dlpi/en:1 and /dev/dlpi/en:3.   
The physical cabing should be as: 


[Node 1003 : en:1 ] ------------+
[            en:3] -------------|---------------------+
                                |                     |
[Node 1004 : en:1] -------------|----+                |
[            en:3] -------------|----|----------------|-----+
                                |    |                |     |
[Node 1005 : en:1]--------------|----|----+           |     |
[            en:3] -------------|----|----|-----------|-----|-----+
                                |    |    |           |     |     |
                   [Priv Switch 1 ]        [Priv Switch 2] 
                     [en1 from 1003,]    [en3 from 1003]
                       [1004, and 1005]    [1004, and 1005]