Features Of E-Iisp; Hierarchy In An E-Iisp Network - 3Com CoreBuilder 9000 User Manual

Features of E-IISP

Hierarchy in an
E-IISP Network
E-IISP includes the following features:


Minimal manual configuration of the switch


Registers addresses of neighboring switches either automatically or
manually


Nodes learn addresses automatically in case of link or node failure


Hierarchic Routing protocol based on hop-by-hop routing, utilizing a
best match scheme


Works with hierarchic network topologies of any size


Prevents network loops


Finds a path to a node if one exists


Crankback mechanism when destination is not found


Allows redundancy and load sharing among nodes
E-IISP also introduced the concept of hierarchy in a network design. Using
E-IISP, most 3Com ATM networks are based in the ATM address of
47.0.0.0.0.0.3c.0.0.a* that is, utilizing the last four bytes of the switch
portion of the ATM address. In the ATM address space, hierarchy
translates into a tree structure as shown in Figure 11. The network core is
designated as the roots of the network and the other switches
subordinate to them are attached as branches. In Figure 11, A, B, and C
are the switches that comprise the network core. Each subordinate switch
can also have switches attached to it. As you progress down the
hierarchy, the node name (or ID) is lengthened to include the parent
node. Finally, all of the roots (A, B, and C) are connected together to
ensure that every node can reach every other node.

Hierarchy in an E-IISP Network

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