Re: EIGRP SIA

In IOS 12.3T whatever code they implemented SIA queries and replies and they
are enabled by default that will take care of portion of this issue, but you
still need the "stub" because from what i remember, the SIA queries/replies
only happen between the router that lost its "S" and had no "FS" (Let's say
R1) and the neighbor to which it is directly connected to (Let's say R2).
But this did not effect R2 and R3 (A downstream neighbor to R2). So Stub is
a real good choice. You could also play with the timers "Timers
active-time" and increase the time that a router waits to hear a reply after
sending a query, if you increase it to 60 minutes and you still get into SIA
issues you have other serious problems.
I personally don't care that much for the "Stub" configuration because of
its behavior, but hey......you do what needs to be done.

On Mon, Jun 21, 2010 at 10:14 AM, Carlos G Mendioroz <tron_at_huapi.ba.ar>wrote:

> In my experience, I made a "click" when I understood that a query
> is answered right away when the neighbour "never heard of this" route.
> (Or has another successor or FS for it)
> That's why summarization is so important. But even with good
> summarization, queries go all way around, even past the summarization
> point (1 hop past it), so stubs deal with them nicely: no questions
> to this neighbour, ever. :)
>
> -Carlos
>
> swap m @ 21/06/2010 13:11 -0300 dixit:
> > @masroor - its worth reading eigrp SIA rewrite feature and understand
> > how it helps to maintain eigrp adjacency intact between non-inflicted
> > neighbors.
> >
> > Swap
> > #19804 x2
> >
> > On Mon, Jun 21, 2010 at 4:31 AM, Adrian Brayton <abrayton_at_gmail.com>
> wrote:
> >> Just to add to what Paul said... What he said was VERY important! Take
> for example you have 2 directly connected neighbors and they will not form
> an adjacency because they are SIA. You will be banging your head against the
> wall trying to figure out why but the reason is some router 5,6-10 hops away
> that is causing the issue. Just something to think about when it comes to
> TS!
> >>
> >>
> >> Sent from my iPad
> >>
> >> On Jun 20, 2010, at 8:17 PM, Paul Negron <negron.paul_at_gmail.com> wrote:
> >>
> >>> This is why we deploy features like EIGRP Stub and Summarization. They
> would
> >>> help to stabilize the network by suppressing certain routes so that
> little
> >>> changes would not be seen.
> >>>
> >>> Paul
> >>> --
> >>> Paul Negron
> >>> CCIE# 14846 CCSI# 22752
> >>> Senior Technical Instructor
> >>> Www.micronicstraining.com <http://www.micronicstraining.com/>
> >>>
> >>> On 6/20/10 5:35 PM, "masroor ali" <masror.ali_at_gmail.com> wrote:
> >>>
> >>>> thanks for the comments, and for the link.
> >>>>
> >>>> actually i had a little confusion in this, if a router send a query
> mesg to
> >>>> all its neighbor routers to find the other path, and neighbor dont
> reply to
> >>>> that router, then the router would clear its neighbor adjacency. it
> means
> >>>> that if there is a big network of many routers and for instance SIA is
> >>>> happening again and again , it means there is inconsistency in
> network???
> >>>> how would we overcome this situation???
> >>>>
> >>>> On Mon, Jun 21, 2010 at 3:55 AM, Muzammil Malick <malickmuz_at_gmail.com
> >wrote:
> >>>>
> >>>>> Sorry, I sent the incorrect link
> >>>>>
> >>>>>
> >>>>>
> http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008010f016
> .
> >>>>> shtml
> >>>>> <
> http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008010f016
> >>>>> .shtml>
> >>>>>
> >>>>> On 20 June 2010 23:44, Muzammil Malick <malickmuz_at_gmail.com> wrote:
> >>>>>
> >>>>>> Hi Masroor
> >>>>>>
> >>>>>> If a router running EIGRP loses the route through its successor and
> does
> >>>>>> not have any feasible successor it will query all of its EIGRP
> neighbors
> >>>>>> for an alternative route i.e. the route is now active (rather than
> >>>>>> passive) and the router is actively querying its neighbors for an
> >>>>>> alternative
> >>>>>>
> >>>>>> If all of its neighbors reply then there is no problem.
> >>>>>> However if for some reason, the router does not receive a reply to
> its
> >>>>>> query from a particular neighbor, it will go into SIA for the
> queried route
> >>>>>> and will clear the neighbor adjacency for the router
> >>>>>> it did not receive a response from.
> >>>>>>
> >>>>>> Have a read of this link, it should clear things up:
> >>>>>>
> >>>>>>
> >>>>>>
> http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008010f016
> >>>>>> .shtml#whydisappear
> >>>>>>
> >>>>>> HTH
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> On 20 June 2010 22:56, masroor ali <masror.ali_at_gmail.com> wrote:
> >>>>>>
> >>>>>>> hi,
> >>>>>>>
> >>>>>>> could anyone would like to make me understand EIGRP SIA in easy
> >>>>>>> wordings??
> >>>>>>>
> >>>>>>> thanks
> >>>>>>>
> >>>>>>> Regards,
> >>>>>>> Masroor Ali
> >>>>>>>
> >>>>>>>
> >>>>>>> Blogs and organic groups at http://www.ccie.net
> >>>>>>>
> >>>>>>>
> _______________________________________________________________________
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> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>> --
> >>>
> >>>
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> >>>
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> >
> >
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> >
> >
> >
> >
> >
>
> --
> Carlos G Mendioroz <tron_at_huapi.ba.ar> LW7 EQI Argentina
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
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>
>
>
>
>
>
>
>

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