Because of the level of the exam being studied for here I'm geussing that
its not referring to BGP, although it could be.. it sounds more like they
may be refferring to this...
This is an exerpt from the Cisco Press ACRC book. page 197
OSPF
Sometimes a link, such as a serial line, will go up and down rapidly (called
flapping), or a link-state change may affect another series of links. In
these situations, a series of LSUs could be generated, which would cause
routers to repeatedly recompute a new routing table. This flapping could be
so serious that the routers would never converge (exchange). To minimize
this problem, each time an LSU is received, the router waits for a period of
time before recalculating its routing table. The SPF HOLDTIME command was
added to the Cisco IOS software to prevent routers from computing a new
routing table until 10 seconds (default) after a route change...
HTH
Cory
-----Original Message-----
From: Tia Crawford [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, June 20, 2000 2:57 PM
To: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: Re: Link Flapping
Marco-
I never came across this terminology either until I was reading some notes
on the sitamoht website. This an excerpt from the sitamoht site....
Route dampening is a BGP feature designed to minimize the propagation of
flapping routes across an internetwork. A route is considered to be flapping
when it is repeatedly available, then unavailable, then available, then
unavailable, and so on.
A route that is flapping receives a penalty of 1000 for each flap. When the
accumulated penalty reaches a configurable limit, BGP suppresses
advertisement of the route even if the route is up. The accumulated penalty
is decremented by the half-life time. When the accumulated penalty is less
than the reuse limit, the route is advertised again (if it is still up).
Tia
>From: "Marco Rodrigues" <[EMAIL PROTECTED]>
>Reply-To: "Marco Rodrigues" <[EMAIL PROTECTED]>
>To: [EMAIL PROTECTED]
>Subject: Link Flapping
>Date: Sun, 18 Jun 2000 16:10:07 -0400
>
>Hey all, i've looked in the archives and can't really find an answer. I'm
>currently studying for my CCDA and I was doing a BOSON test question and I
>came accross the term, link flapping in coherence with Convergence. I've
>never heard that term, i've looked at the Appendices/Glossary of my CCDA
>book and in the archives of this mailing list and couldn't find an answer.
>Just curious does this word even exsist? If so how does it relate to
>convergence.
>
>Thanks!
>
>
>--
>-------------------------------------
>Marco Paulo Rodrigues
>Junior Unix Systems Operator
>Axxent Corporation
>www: http://www.axxent.ca
>Email: [EMAIL PROTECTED]
>Work Phone : 1 + (416) 907-2880
>TSE Stock Symbol : axi.b
>-------------------------------------
>
>
>___________________________________
>UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html
>FAQ, list archives, and subscription info: http://www.groupstudy.com
>Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
___________________________________
UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html
FAQ, list archives, and subscription info: http://www.groupstudy.com
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
___________________________________
UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html
FAQ, list archives, and subscription info: http://www.groupstudy.com
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
