Chapter 9: AI2524 OSI/CLNP Configuration Steps
August 1997 Page 9-31
2524UM
quickly a failed link or neighbor is detected so that routes can be recal-
culated.
In interface configuration mode, set the advertised hello interval and
multiplier:
1. Specify the length of time, in seconds, between hello packets th
software sends on the specified interface.
isis hello-interval
seconds
{level-1 |
level-2}
2. Specify the number used to multiply the hello interval seconds by
to determine the total holding time transmitted in the IS-IS hello
packet. If not specified, a multiplier of 3 is used.
isis hello-multiplier

multiplier

[{level-1
| level-2}]
The hello interval can be configured independently for Level1 and
Level2, e xcept on serial point-to-point interfaces. (Because there is
only a single type of hello packet sent on serial links, the hello packet
is independent of Level1 or Lev el2.) Specify an optional level for
X.25, SMDS, and Frame Relay multi access net works.
Use the isis hello-multiplier command in circumstances
where hello packets are lost frequent ly and IS-IS adjacencies are fail-
ing unnecessarily. You can raise the hello multiplier and lower th
hello interval (isis hello-interval command) correspond
ingly to make the hello protocol more reliable without increasing th
time required to detect a link failure.
Set the Advertised CSNP Interval
CSNPs are sent by the designated router to maintain databa se s ynchro-
nization.
In interface config ura tion mo de, c onfi gure t he I S-IS C SNP interva l fo
the interface:
isis csnp-interval
seconds
{level-1 |
level-2}
This feature does not apply to serial point-to-point interfaces. It does
apply to WAN connections if the WAN is viewed as a multiaccess
meshed network.