AI2524 Router Card User’s Manual
Page 9-18 August 1997
2524UM
Warning: Adjusting the ISO IGRP metric c an dramatically affect
network performance, so ensure that all metric adjust-
ments are made carefully. Because of t he complexity of
this task, it is not recommended unless it is done with
guidance from an experienced system desi gner.
You can use different metrics for the ISO I GRP routing protocol on
CLNS. In router configuration mode, config u re the metric constants
used in the ISO IGRP composite metric calculation of reliability and
load:
metric weights

qos k1 k2 k3 k4 k5

Two additional ISO IGRP metrics can be configured: the bandwidth
and delay associated with an inte rface.
Warning: Using the bandwidth and delay commands to change
the values of the ISO IGRP met rics also changes the val-
ues of IP IGRP metrics.
Adjust ISO IGRP Timers
The basic timing parameters for ISO IGRP are adjustable. Because the
ISO IGRP routing protocol exec utes a distributed, asynchronous rout-
ing algorithm, it is important that these timers be the same for all rout-
ers in the network.
In router configuration mode, adjust ISO IGRP timing parameters:
timers basic

update-interval holddown-

interval invalidinterval

Enable or Disable Split Horizon
Split horizon blocks information about routes from being advertised
out the interface from which that information originated. This feature
usually optimizes communication among multipl e routers, particularly
when links are broken.
In interface configuration mode, either enable or disable split horizon
for ISO IGRP updates:
zEnable split horizon for ISO IGRP updates.
clns split-horizon