From: Rajeev Siddappa (raj_lab@xxxxxxxxx)
Date: Fri Jan 11 2002 - 05:35:39 GMT-3
Thek,
168.71.x.x is not an external route. It is an eigrp
learned route.
Rajeev.
--- Thek <thek@mediaone.net> wrote:
> My thoughts ..
>
> 1. First wrt to the 168.71.x.x network ..here is the
> explanation as to why
> yu dont see a summary route .........
>
> EIGRP will not auto-summarize external routes unless
> there is a component of
> the same major network that is an internal route
>
> 2. secondly wrt to 20.x.x.x showing up as a Null
> summary route ...
> EIGRP performs an auto-summarization each time it
> crosses a border between
> two different major networks.
>
>
> So basically since yu are learning 168.71.x.x on one
> of your interfaces your
> router will not produce a Summary route for that
> major net but however on
> the other hand 20.x.x.x this does not apply and
> hence yu DO see a summary
> route after all
>
> Am not sure if I have put it across well .... hope
> yu get the point !!
>
> ----- Original Message -----
> From: "Rajeev Siddappa" <raj_lab@yahoo.com>
> To: "Frank B" <frank@buff-net.com>; "'CCIE Lab'"
> <labccie@yahoo.com>
> Cc: "'ccielab'" <ccielab@groupstudy.com>; "'j
> killion'"
> <jkillion1977@yahoo.com>; "'Steven'"
> <adream@163.com>
> Sent: Thursday, January 10, 2002 11:36 PM
> Subject: RE: eigrp auto-summary and a null 0 route
>
>
> > Frank, I understand.
> >
> > Pls see below,
> >
> >
> > > > Auto-summarization only takes place when you
> cross
> > > > classful boundaries.
> >
> >
> > We are not crossing any classful boundaries here.
> > We are still in the same router.
> >
> > > > You have 2 interfaces connected within the
> > > > 168.71.0.0 space; so it sends
> > > > advertisements out those interfaces for
> subnets
> > > > within 168.71.0.0
> >
> >
> > > >
> > > > However, other networks advertised out those
> > > > interfaces are summarized
> > > > on their classful boundary. Hope this helps.
> > > >
> > > > Frank
> > > >
> > > >
> > > > -----Original Message-----
> > > > From: nobody@groupstudy.com
> > > > [mailto:nobody@groupstudy.com] On Behalf Of
> > > > CCIE Lab
> > > > Sent: Thursday, January 10, 2002 7:34 PM
> > > > To: j killion; Steven; ccielab
> > > > Subject: Re: eigrp auto-summary and a null 0
> route
> > > >
> > > > good, but why didn't it also create a summary
> > > route
> > > > to
> > > > null for 168.71.0.0 subnets?
> > > >
> > > > --- j killion <jkillion1977@yahoo.com> wrote:
> > > > > Once you added the "auto-summary" cmd, EIGRP
> > > will
> > > > > now
> > > > > summarize at network boundaries - in this
> case
> > > at
> > > > > 20.0.0.0/8. It creates the summary pointing
> to
> > > > > Null0
> > > > > to stop routing loops from forming.
> > > > >
> > > > >
> > > > > --- Steven <adream@163.com> wrote:
> > > > > > On one router which runs eigrp only ,the
> > > config
> > > > > and
> > > > > > route table is as follows,
> > > > > >
> > > > > > sh run
> > > > > > ...
> > > > > > router eigrp 1
> > > > > > network 20.0.0.0
> > > > > > network 168.71.7.0 0.0.0.255
> > > > > > network 168.71.9.0 0.0.0.255
> > > > > > no auto-summary
> > > > > > no eigrp log-neighbor-changes
> > > > > >
> > > > > > ...
> > > > > >
> > > > > > 168.71.0.0/24 is subnetted, 4 subnets
> > > > > > C 168.71.9.0 is directly connected,
> > > > Serial1
> > > > > > C 168.71.7.0 is directly connected,
> > > > Serial0
> > > > > > D 168.71.6.0 [90/20768000] via
> > > 168.71.9.1,
> > > > > > 00:00:17, Serial1
> > > > > > D 168.71.5.0 [90/20384000] via
> > > 168.71.9.1,
> > > > > > 00:00:17, Serial1
> > > > > > 20.0.0.0/24 is subnetted, 1 subnets
> > > > > > C 20.1.1.0 is directly connected,
> > > > Loopback0
> > > > > >
> > > > > >
> > > > > > after i add "auto-summary "command under
> > > router
> > > > > > eigrp 1
> > > > > >
> > > > > > the route table change to the following
> one ,
> > > > > >
> > > > > > 168.71.0.0/24 is subnetted, 4 subnets
> > > > > > C 168.71.9.0 is directly connected,
> > > > Serial1
> > > > > > C 168.71.7.0 is directly connected,
> > > > Serial0
> > > > > > D 168.71.6.0 [90/20768000] via
> > > 168.71.9.1,
> > > > > > 00:00:03, Serial1
> > > > > > D 168.71.5.0 [90/20384000] via
> > > 168.71.9.1,
> > > > > > 00:00:03, Serial1
> > > > > > 20.0.0.0/8 is variably subnetted, 2
> > > > subnets,
> > > > > 2
> > > > > > masks
> > > > > > D 20.0.0.0/8 is a summary, 00:00:01,
> > > Null0
> > > > > > C 20.1.1.0/24 is directly connected,
> > > > > Loopback0
> > > > > >
> > > > > >
> > > > > > i just want to know what "D
> 20.0.0.0/8
> > > is
> > > > a
> > > > > > summary, 00:00:01, Null0"
> > > > > > mean.Why is it added?
> > > > > >
> > > > > >
> > > > > >
> > > > > > Thanks.
> > > > > >
> > > > >
> > > >
> > >
> >
>
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:56:24 GMT-3