From: Baety Wayne SrA 18 CS/SCBX (Wayne.Baety@xxxxxxxxxxxxx)
Date: Mon Jul 01 2002 - 04:07:20 GMT-3
I added 'passive-interface loopback2' to avoid extra debug output. But
before I did that the router did not generate a summary for loopback2 even
though I tested the config by placing the same summary command on the
loopback2 interface. This kind of configuration of a summary in conjunction
with disabling split-horizon in a production environment is error prone,
because normally the pruning of received advertisements from going out of
the received interface avoids routing loops. Even though it is a summary
address and not the original more specific route, a routing loop can develop
(followed by an eventual router reboot).
For instance, the packets will bounce back between the destination router
and the router configured with the summary, if the router on which the
summary is configured has a more specific route to a destination pointing
out on the same interface and the eventual destination router (or any
intermediary) has the 'no ip classless' command configured along with the
possibility of not having complete knowledge of all subnets of the major
network in which summary address is configured.
But in order to advertise the summary out of the interface in which at least
1 advertisement is received matching the major network address, then yes,
you would need to disable split-horizon on that interface. Otherwise the
expected behavior is as it should: the summary is advertised out of other
interfaces (configured with the summary address) and split horizon is
irrelevant in the issue of him not being able to generate a rip summary.
WAYNE A. BAETY, SRA, MCSE, USAF
18th Communications Squadron
DSN: 634-9927
Commercial: 011 81 611 734 9927
-----Original Message-----
From: Lab Candidate [mailto:labccie@yahoo.com]
Sent: Monday, July 01, 2002 2:57 PM
To: Baety Wayne SrA 18 CS/SCBX; ccielab@groupstudy.com;
irene.golbery@arche.fr; louis.krucker@sunrise.net
Cc: p729@cox.net
Subject: RE: rip summary-address
Wayne, I thought you need to disable split-horizon before the summary-addr
is advertised out on
the interface. If that's not the case, then your test proves none of the
restrictions have to be
obeyed in this RIP v2 address summary feature, isn't it true?
--- Baety Wayne SrA 18 CS/SCBX <Wayne.Baety@kadena.af.mil> wrote:
> Of course always test a hypothesis....
>
> interface Loopback1
> ip address 172.17.5.1 255.255.255.0
> ip summary-address rip 172.31.0.0 255.255.0.0
> !
> interface Loopback2
> ip address 172.31.1.1 255.255.255.0
> ip address 172.31.3.1 255.255.255.0 secondary
>
> router rip
> version 2
> passive-interface Loopback2
> network 172.17.0.0
> network 172.31.0.0
> no auto-summary
>
>
> RELEVANT DEBUG OUTPUT before ip summary-address rip:
>
> 1w0d: RIP: sending v2 update to 224.0.0.9 via Loopback1 (172.17.5.1)
> 1w0d: RIP: build update entries
> 1w0d: 172.31.1.0/24 via 0.0.0.0, metric 1, tag 0
> 1w0d: 172.31.3.0/24 via 0.0.0.0, metric 1, tag 0
> 1w0d: RIP: Update contains 2 routes
>
> RELEVANT DEBUG OUTPUT after ip summary-address rip:
>
> 1w0d: RIP: sending v2 update to 224.0.0.9 via Loopback1 (172.17.5.1)
> 1w0d: RIP: build update entries
> 1w0d: 172.31.0.0/16 via 0.0.0.0, metric 1, tag 0
> 1w0d: RIP: Update contains 1 routes
>
> ...notice that Loopback1 is not on the same major class net as the
> advertised routes.
>
> I think he's simply just using an old IOS version, haven't seen anything
> about this in the Bug Track.
>
> WAYNE A. BAETY, SRA, MCSE, USAF
> 18th Communications Squadron
> DSN: 634-9927
> Commercial: 011 81 611 734 9927
>
>
> -----Original Message-----
> From: Lab Candidate [mailto:labccie@yahoo.com]
> Sent: Monday, July 01, 2002 12:25 PM
> To: ccielab@groupstudy.com; irene.golbery@arche.fr;
> louis.krucker@sunrise.net
> Cc: p729@cox.net
> Subject: Re: rip summary-address
>
> What Mas said is correct about the restrictions of RIPv2 summary.
> I'm just wonderring what if you want to summarize multiple routes on the
> same interface.
> On CCO, it states that Each route summarization on an interface must have
a
> unique major net,
> whether or not the addresses have unique address masks.
> But how can you keep each route summary with unqiue major net and also
share
> the same major net as
> that of the interface it's summarized on?
> Any thoughts?
>
>
>
> In addition to disabling split horizon, the summary address and the
> interface it is being advertised on must share the same major net.
>
> Regards,
>
> Mas Kato
> https://ecardfile.com/id/mkato
> ----- Original Message -----
> From: "Krucker, Louis" <louis.krucker@sunrise.net>
> To: "'GOLBERY Irhne '" <irene.golbery@arche.fr>; <ccielab@groupstudy.com>
> Sent: Sunday, June 30, 2002 9:20 AM
> Subject: RE: rip summary-address
>
>
> > Hello group
> >
> > Heres my config:
> >
> > The goal is to advertse one single route over e0 ( 172.31.0.0 / 16 )
> >
> > This config dont works in my lab, all single routes are advertised over
> > e0, even if i disable split horizon.
> >
> > Please correct me if i am wrong, may i dont get the point and i must use
> > another strategy.
> >
> > int e0
> > ip address 172.17.5.1 255.255.255.0
> > ip summary-address rip 172.31.0.0 255.255.0.0
> >
> > int loopback 1
> > ip address 172.31.2.1 255.255.255.0
> >
> > int loopback 2
> > ip address 172.31.3.1 255.255.255.0
> >
> > router rip
> > version 2
> > no auto-summary
> > network 172.17.0.0
> > network 172.31.0.0
> >
> > Thanks
> >
> > Louis
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > -----Original Message-----
> > From: GOLBERY Irhne
> > To: Krucker, Louis; 'ccielab@groupstudy.com'
> > Sent: 30.06.2002 17:56
> > Subject: RE: rip summary
> >
> >
> > My understanding
> >
> > It is used in Network Access Server context and not for summarisation
> > like
> > we used to do in other routing protocol.
> >
> >
> > Example : 10 remote users connecting to a central router , in order not
> > to
> > have 10 hosts entry in the routing table of the central router you can
> > use
> > this command to summarize and only have a network or subnet entry in the
> > RIB
> >
> >
> > Correct me if i am wrong ?
> >
> > Irene
> >
> >
> >
> >
> > -----Message d'origine-----
> > De : Krucker, Louis [mailto:louis.krucker@sunrise.net]
> > Envoyi : dimanche 30 juin 2002 17:13
> > @ : 'ccielab@groupstudy.com'
> > Objet : rip summary
> >
> >
> > Hi Group
> >
> > I use rip v2 and no auto-summary, how the command ip rip summary-address
> > will work in this case. I did'nt found a detailed documentation in the
> > archive or at cco.
> >
> > This command does not work in my lab, i try to advertise a summary
> > route.
> > Are there any hints ? Even if i disable split-horizon no summary is
> > advertised. If i look in the rip database the route is there.
> >
> > Thanks for help
> >
> > Louis
This archive was generated by hypermail 2.1.4 : Sat Sep 07 2002 - 19:36:16 GMT-3