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Re: My virtual-link question
Don,
I was talking about two general methods
of handling overload, thus it was a FYI...
Doing one, both, or none is a implimentation
issue for your company.
Mitchell Erblich
----------------
Don Goodspeed wrote:
>
> Mitchell,
>
> Why would a router advertising a virtual-link as one of it's
> possibly many links MaxAge it's entire router LSA?
>
> And in the example that I gave, the router with the virtual-
> link was not the one in overload. In fact, I made a note
> at the end of my original description that one could have
> a virtual-link path where the total path cost exceeded 65535
> and my question applied to that scenario as well.
>
> Should the end-points of the virtual-link tear down the
> virtual-link in this case, or advertise the virtual-link
> with the largest advertisable cost in a TOSMetric field
> of a router LSA which is 65535.
>
> I think you and I are thinking of two different scenarios.
>
> Cheers,
> Don
>
> -----Original Message-----
> From: Mailing List [mailto:OSPF at PEACH.EASE.LSOFT.COM]On Behalf Of
> Erblichs
> Sent: Friday, July 30, 2004 6:20 PM
> To: OSPF at PEACH.EASE.LSOFT.COM
> Subject: Re: My virtual-link question
>
> Don,
>
> MAXAGE is used to withdraw a link from the LSDB.
> It is normally done when the SEQ is Maxed out.
>
> If a router is indeed OVERLOADED and unable to
> route even the fewest of transit packets and/or
> dst packets, then it is easily concieveable not
> to waste the bandwidth of to the destinations
> knowing those packets are going to be dropped
> anyway. Worst case is a drop at the last hop.
>
> You are in effect voluntering blackholing those
> routes until your router is able to advertise them
> again. It is a very drastic move which forces a new
> convergence to take place. It also assumes that
> you can still generate the advertisement. The same
> will happen if you don't refresh the routes in
> 1 hours timeframe.
>
> Please be aware that this is different from DNA
> (do not age) LSAs.
>
> The MAXCOST metric via the Stub Router Advertisement
> only minimizes the number of transit pkts, but with
> no alternatives does not decrease the amount of
> transit traffic. It does not effect pkts that are
> routed only to a dst that is attached thru the
> router.
>
> I thought you would like to see how to do both of
> your items.
>
> Mitchell Erblich
> -------------------
>
> Don Goodspeed wrote:
> >
> > All,
> >
> > My excite account was on the fritz so I resubscribed with my work account.
> >
> > Mitchell, the last email I saw said advertise the link with MAXAGE.
> >
> > Did you mean to say MaxMetric (aka 0xffff)?
> >
> > -don