3Com CoreBuilder 7000, Руководство по эксплуатации

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58 C
HAPTER
3: E-IISP P
ROTOCOL
Configuring Network
ATM Addresses
After the addressing scheme is established, you use either the Integrated
Fast Setup procedure or specific LMA commands (see “Update Network
Prefix” on page 63 in the Management Guide) to register the network
prefixes at each CoreBuilder 7000 family ATM switch. See the Corebuilder
7000 Family ATM Switches Installation and Setup Guide for a detailed
description of the Integrated Fast Setup procedure.
Auto-Discovery After each switch in the hierarchical network has received and registered
its own hierarchical ATM address network prefix, the switch will discover
who its neighbors are and update its routing table to include its
neighbors’ information. This process is called
auto-discovery . The
auto-discovery function ensures that the neighboring switches get this
information. Each CoreBuilder 7000 family ATM switch periodically
transmits a SET command containing its network prefix to each
connection via the ILMI channel (0,16). Each of its neighboring
CoreBuilder 7000 family ATM switches receives the message and stores
the received network prefix together with the port number on which the
message was received.
In this way, each CoreBuilder 7000 family ATM switch knows the network
prefix of each of its neighbors. For example, in Figure 10, switch A
registers the ATM address prefixes of the three neighbors A1, A2, and B.
Similarly, switch B registers the prefixes of A, B1, and B2.
Auto-Configuration After the switch has “discovered” its neighbor it will configure its
interface protocol to match its neighbor in the lowest common
denominator. This process is called
auto-configuration . If one switch is
configured as IISP and the other switch is configured as E-IISP, then both
switches will configure themselves to IISP.
Static Address
Registration in E-IISP
Static addresses must be registered manually by the LMA (see “Add ATM
Address to Port” on page 160 in the Management Guide).
Planning a Network
with E-IISP
This section discusses the elements of planning a network using the E-IISP
protocol. There are four basic elements to take into account when
planning a network:
Hierarchical topology
Preparation of alternate routes
Load balancing