Subject: Re: Holdtime in Hello Message

From: Bill Fenner <[email-masked]>
Date: Thu, 30 Nov 2000 17:50:29 -0800

>However, in the new re-written spec I noticed that it says that the router
>can use either the Holdtime sent by the neighbor or the local
>[Hello-Holdtime] in case the Hello packet didn't have the Holdtime. What if
>the local [Hello-Holdtime] is different from the neighbor's? 

Then your subnet is misconfigured and may not work properly.
PIM routers should include the Holdtime option in Hellos when 
their Hello_Period is different than the default in the spec,
in order to prevent such misconfigurations.

>Is it mandatory that Hello packets carry the Holdtime? 

Not if it is the default.
  
>Do PIM implementations ignore Hello packets with no Holdtime? 
  
Good question; this is a place to check compatability between old
spec and new (since the old spec says you copy the hold time from
the option and doesn't say what to do if it's not there).

  Bill