Extension nodes are non-standard nodes that extend the SP system's capabilities or scope, but cannot be used in all the same ways as standard SP nodes.
A specific type of extension node is a dependent node. Dependent nodes are attached to the SP Switch via a special dependent node adapter. The SP Switch2 does not support extension nodes.
A dependent node implements much of the switch-related protocol that standard nodes use on the SP Switch, but it depends on standard SP nodes for certain functions. A dependent node can use the SP Switch as an IP network, but it relies upon a standard SP node to generate its switch route table. (The communication subsystem does not send dependent nodes switch topology database updates, but rather generates and sends appropriate switch route tables.)
SNMP support provides for the communication of switch-related configuration information between the SP system and the dependent node.
A dependent node cannot be a primary or primary backup node for the SP Switch.
The CSS_test, Efence, and Eunfence commands operate on dependent nodes in the same way they operate on standard nodes. The Eprimary command returns an error message if a dependent node is specified for a primary or primary backup node for the SP Switch. The Eannotator command notes dependent nodes in the annotated topology file.
For more information on extension nodes and dependent nodes, refer to Chapter 18, Managing extension nodes.