From: Narbik Kocharians (narbikk@gmail.com)
Date: Thu Jul 06 2006 - 14:33:04 ART
There are some vendors that implement RFCs and some that don't, Cisco
decided to implement the RFC for the reason i mentioned and thats why its
available on WAN and not LAN interfaces.
You mean that the "ip rip triggered" command does not suppress the updates
so it does not consume BD? I guess this guys in Cisco did not test it as
well?
http://www.cisco.com/en/US/products/sw/iosswrel/ps1830/products_feature_guide09186a008008746f.html
By the way you stated that this command is not supported on multipoint, i
have to totally disagree with that as well. When you configure frame-relay
directly under the physical interface, isn't that considered a multipoint?
Therefore, it's not an issue of P2P Vs Multipoint, its LAN versus WAN.
Narbik Kocharians
CCIE# 12410 (R&S, SP, Security)
CCSI# 30832
Network Learning, Inc. (CCIE class Instructor)
www.ccbootcamp.com (CCIE Training)
On 7/6/06, Brian McGahan <bmcgahan@internetworkexpert.com> wrote:
>
> Triggered extensions to RIP are not a Cisco specific feature;
> they are defined in RFC 2091.
>
> http://www.internetworkexpert.com/rfc/index.php?rfc=2091
>
> If you read through the RFC and tested the behavior you would
> see that your explanation is not correct.
>
> Routes in the RIP database learned on an interface running
> triggered extensions behave like DNA LSAs in the OSPF database. In
> other words the invalid timer does not apply to them. Instead RIP
> relies on the point-to-point nature of the WAN link to invalidate
> installed updates when the link goes down.
>
> As Brian pointed out this configuration is not valid on
> multipoint interfaces because the layer 1 status of the interface does
> not necessarily reflect end-to-end reachability on the segment, i.e. one
> side of the link can be up while the other side is down.
>
>
>
> HTH,
>
> Brian McGahan, CCIE #8593
> bmcgahan@internetworkexpert.com
>
> Internetwork Expert, Inc.
> http://www.InternetworkExpert.com
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>
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
> Of
> > Narbik Kocharians
> > Sent: Thursday, July 06, 2006 11:47 AM
> > To: Brian Dennis
> > Cc: Sami; ccielab@groupstudy.com
> > Subject: Re: RIP triggered
> >
> > RIP does not care if the other end point is down or not, if RIP does
> not
> > receive the updates from a router on a point-to-point or multipoint
> > interface, it has two timers that it will use to handle that
> situation,
> > invalidation timer and Flush timer.
> >
> > There are two reasons that Cisco came up with this extension:
> >
> > The periodic updates (every 30 seconds be default) can keep the
> circuit
> > up,
> > and the second reason is to cut down on the number of periodic updates
> > even
> > on a Point-to-point connections.
> > Its because of these two points that the command "ip rip triggered" is
> > only
> > available on the wan interfaces and it has nothing to do with neighbor
> > down
> > detection, it has provisions for that already. I am sorry but I have
> to
> > disagree.
> >
> > Narbik Kocharians
> > CCIE# 12410 (R&S, SP, Security)
> > CCSI# 30832
> > Network Learning, Inc. (CCIE class Instructor)
> > www.ccbootcamp.com (CCIE Training)
> >
> >
> > On 7/6/06, Brian Dennis <bdennis@internetworkexpert.com> wrote:
> > >
> > > Think about it like this. If you run RIP triggered across a P2P
> serial
> > > link and the remote end goes down, your local interface should also
> go
> > > down. This will allow your local router to detect that the remote
> > > router's routes should be removed from the routing table. Now if
> it's a
> > > multipoint interface like Ethernet (more than one endpoint possible)
> > > then if the remote router goes down, the Ethernet interface will not
> > > normally go down assuming a hub or switch is being used. This means
> > > that even though the remote router is down, its routes will not be
> > > removed from your local router's routing table since you are not
> > > expecting periodic updates and you can not determine based on the
> > > interface state if the remote router is down.
> > >
> > > HTH,
> > >
> > > Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
> > > bdennis@internetworkexpert.com
> > >
> > > Internetwork Expert, Inc.
> > > http://www.InternetworkExpert.com
> > > Toll Free: 877-224-8987
> > > Direct: 775-745-6404 (Outside the US and Canada)
> > >
> > >
> > > -----Original Message-----
> > > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
> Of
> > > Sami
> > > Sent: Thursday, July 06, 2006 4:56 AM
> > > To: ccielab@groupstudy.com
> > > Subject: RIP triggered
> > >
> > > Group,
> > >
> > > ip rip triggered command is not under ethernet interface ? is there
> any
> > > speific reason for not having it ?
> > >
> > > R4(config)#int fastEthernet 0/0
> > > R4(config-if)#ip rip ?
> > > advertise Specify update interval
> > > authentication Authentication control
> > > receive advertisement reception
> > > send advertisement transmission
> > > v2-broadcast send ip broadcast v2 update
> > >
> > > R4(config)#int s0/0/0
> > >
> > > R4(config-if)#ip rip ?
> > > advertise Specify update interval
> > > authentication Authentication control
> > > receive advertisement reception
> > > send advertisement transmission
> > > triggered enable rfc2091 triggered rip
> > > v2-broadcast send ip broadcast v2 update
> > >
> > >
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