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RE: ISIS Hello Packet Problem posted 11/21/2003
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See below.

-----Original Message-----
From: Jonathan V Hays [mailto:jhays@xxxxxxxx]
Sent: 20 November 2003 21:52
To: Ken.Farrington@xxxxxxxxxxxxxxxxxxx; ccielab@xxxxxxxxxxxxxx
Subject: RE: ISIS Hello Packet Problem

On the same page, it also says "The hello interval is jittered, up to
about 25 percent to reduce the likeliness of synchronized IIH
transmission over the network."

>From the above information, I would guess that the DIS (designated
intermediate system) ignores the "isis hello-interval" command and sends
at 3.3 seconds (plus or minus 25% jitter) regardless. The other side is


Just to clear up a minor error in my own post, where I said "plus or
minus." It should read "at 3.3 seconds (MINUS 25% jitter)" since the
random interval is subtracted, never added.

To those who are not aware of this, other protocols (such as RIP) do the
same thing with their updates, to avoid synchronization.