From: blodwick (blodwick@columbus.rr.com)
Date: Sun Mar 05 2006 - 21:03:43 GMT-3
The only difference is what triggers the event. It's the same algorithm.
BGP dampening - BGP route flap triggers it, and only affects BGP.
Interface dampening - interface flap triggers it, and it affects RIP,
OSPF, EIGRP, IS-IS, BGP, CLNS, and HSRP.
Brian L.
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
sameer azam
Sent: Sunday, March 05, 2006 10:53 AM
To: Petr Lapukhov
Cc: ccielab@groupstudy.com
Subject: Re: Dampening on the interface
HI,
Guys i was talking about the DAMPENING on the INTERFACE
not in the BGP, which is different .
regards
On 3/5/06, Petr Lapukhov <petrsoft@gmail.com> wrote:
>
> Hi,
>
> hm, let's see :)
>
> If we got 1000 for every flap, then for 3 quick flaps in a row,
> theoretically, we accumulate 3000. If Suppress value is set to 2000
> then after those three flaps we got our interface suppressed. Now
> penalty starts to decay exponentially by simple law
>
> CurrentPenalty = StartPenalty*2^(-t/HLife) (it halves every HLife
time)
>
> Interface become unsuppressed when CurrentPenalty hits ReuseValue.
>
> Now, half of 3000 is 1500, and thus, by setting Half-Life to 30 secs,
and
> Reuse Value
> to 1500, we could get close to desired result.
>
> dampening 30 1500 2000 100
>
> Why MaxSuppressTime is 100? Well maximum _possible_ PenaltyValue is
20000.
> and our
>
>
> MaxPenalty = ReuseV*2^(MaxST/HLife) - this is the penalty value,
> which decays to ReuseValue in MaxSuppressTime.
>
> So setting MaxST to 100, brings MaxPenalty below the possible limit,
but
> setting it to 120, makes MaxPenalty jump over.
>
>
> HTH
> Petr
>
> ---
>
>
> 2006/3/5, sameer.azam@gmail.com <sameer.azam@gmail.com>:
>
> > Hi,
> >
> > Is there is a Way to calculate the value of DAMPENING command, such
as
> >
> > Half Life
> > Reuse Limit
> > suppress-threshold
> > max-suppress-time
> >
> > Ok Wt i know from the command reference is that
> >
> > Max-suppress-time = 4 x Half Life
> >
> > But how to answer the following Question:
> >
> > Dampen the route when the link flaps 3 times then suppress the
> > route for 30 Sec.
> >
> > Regards
> >
> >
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