Re: Auto RP with sparse-mode and no dm-fallback..and its

The receiving router doesn't matter. The middle one does.

So is your middle one in sparse-only on its interface? Does that one
have the listener?

If the answers are yes, and no, respectively, then it shouldn't forward
the traffic on. We run a similar scenario in one our bootcamp labs, and
it's all sorts of fun. :)

When you do "show ip pim rp mapping" who does it say the source of info
is? In other words do you have more than one MA by chance?

*Scott Morris*, CCIE/x4/ (R&S/ISP-Dial/Security/Service Provider) #4713,

JNCIE-M #153, JNCIS-ER, CISSP, et al.

JNCI-M, JNCI-ER

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Mohamed El Henawy wrote:
> Hello Roy ,
>
> Thanks for your comments...the funny thing is that I added router behind R2
> and run sparse mode and it was learning the mapping too. as per your last
> point this router shouldn't be... I don't put auto rp listener
>
>
> ----- Original Message -----
> From: Roy Waterman
> To: Mohamed El Henawy
> Cc: ccielab_at_groupstudy.com
> Sent: Friday, August 28, 2009 12:51 PM
> Subject: Re: Auto RP with sparse-mode and no dm-fallback..and its working
>
>
> Hi Mohamed
> This info is partly based on my tests, so ppl feel free to disagree:
>
> Any routers directly connected to a mapping agent that are PIM neighbors of
> the mapping agent will receive the rp discovery messages regardless of pim
> mode.
> This is because the mapping agent floods the RP to group mapping out all pim
> enabled interfaces (even out loopback ints).
> As a result, directly connected routers will receive the group to rp
> mapping.
> However the directly connected routers will not send rp discovery messages
> to any downstream routers unless:
>
> The directly connected router has a downstream interface running
> sparse-dense or dense mode
> or
> The directly connected router is running ip pim autorp listener
>
> This explains why in your scenario, R2, which is directly connected to your
> mapping agent, receives the rp discovery messages.
> If you connect a downstream router off R2, and only run pim sparse mode on
> the interface to the downstream router and keep ip pim autorp listener
> disabled, you should observe the same behaviour outlined above.
>
>
> Regards
> Roy
>
>
>
>
> The key is whether the router that is directly connected to the mapping
> agent chooses to take any action based
>
>
>
> 2009/8/27 Mohamed El Henawy <m.henawy_at_link.net>
>
> so why we use BSR ...i thought we used it when we couldn't use Auto RP (
> no sparse dense mode )
>
>
> ----- Original Message -----
> From: Roy Waterman
> To: Mohamed El Henawy
> Cc: Mark Matters ; Keegan.Holley_at_sungard.com ; G2 ; Cisco certification
> ; nobody_at_groupstudy.com
> Sent: Thursday, August 27, 2009 1:00 PM
> Subject: Re: Auto RP with sparse-mode and no dm-fallback..and its
> working
>
>
> Hi Mohamed
>
> Regarding your point:
>
> -------------
> Without any pings from R2 to this group there is maping ...Auto RP sent
> > the update via maping agent R0 to R2
> -------------
>
> Pinging a multicast group has no relevance to RP announce or discovery
> messages.
> R2 is automatically listening to group 224.0.1.40 when PIM was enabled
> on an interface.
> As R0 sends RP discovery messages to 224.0.1.40, R2 learns of the group
> to rp mappings.
>
>
>
> 2009/8/27 Mohamed El Henawy <m.henawy_at_link.net>
>
> Hello Roy ,
>
> yes i configured both to use the loopback 10.10.10.10
>
>
> here is the config
>
> > R1-----LAN-----R0-----FR------R2
> > R1
> > FastEthernet0/0 1.1.1.1 YES manual up up
> > !
> > interface FastEthernet0/0
> > ip address 1.1.1.1 255.255.255.0
> > ip pim sparse-mode
> > ip igmp join-group 224.11.11.11
> > duplex auto
> > speed auto
> >
> > R0
> > !
> > interface FastEthernet0/0
> > ip address 1.1.1.2 255.255.255.0
> > ip pim sparse-mode
> >
> > end
> >
> > R0#sh run int s1/0
> > ip address 2.2.2.1 255.255.255.0
> > ip pim sparse-mode
> > encapsulation frame-relay
> > serial restart-delay 0
> > frame-relay map ip 2.2.2.2 101 broadcast
> > end
> >
> > R0#
> >
> > interface Loopback0
> > ip address 10.10.10.10 255.255.255.0
> > ip pim sparse-mode
> > end
> >
> > ip pim send-rp-announce Loopback0 scope 10 group-list 10
> > ip pim send-rp-discovery Loopback0 scope 10
> >
> > R0#sh access-lists 10
> > Standard IP access list 10
> > 10 permit 224.11.11.11
> > R0#
> >
> > R2#
> > !
> > interface Serial1/0
> > ip address 2.2.2.2 255.255.255.0
> > ip pim sparse-mode
> > encapsulation frame-relay
> > serial restart-delay 0
> > frame-relay map ip 2.2.2.1 202 broadcast
> >
> > ip route 10.10.10.10 255.255.255.255 2.2.2.1
> >
> >
> > before this route was aded i get
> >
> > *Mar 1 00:16:39.427: IP(0): s=10.10.10.10 (Serial1/0) d=224.0.1.40
> > id=166, ttl=9, prot=17, len=52(48), RPF lookup failed for source
> >
> >
> >
> > then i correct it and after that i noticed this debug on R2
>
> >
> > RP 10.10.10.10
>
> > *Mar 1 00:19:35.375: MRT(0): Update (*,224.0.1.40), RPF /0.0.0.0
> > *Mar 1 00:19:35.375: MRT(0): Update Serial1/0/224.0.1.40 in the
> olist of
> > (*, 224.0.1.40), Forward state - MAC built
> > *Mar 1 00:19:37.051: MRT(0): Update (*,224.0.1.39), RPF /0.0.0.0
> > *Mar 1 00:19:37.051: MRT(0): Update Serial1/0/224.0.1.39 in the
> olist of
> > (*, 224.0.1.39), Forward state - MAC not built
> > *Mar 1 00:19:38.527: IP(0): s=10.10.10.10 (Serial1/0) d=224.0.1.40
> > id=229, ttl=9, prot=17, len=52(48), mroute olist null
> > *Mar 1 00:19:38.531: Auto-RP(0): Received RP-discovery, from
> 10.10.10.10,
>
> > RP_cnt 1, ht 181
>
> > *Mar 1 00:19:38.531: Auto-RP(0): Update (224.11.11.11/32,
> > RP:10.10.10.10), PIMv2 v1(?), v2v1 ===========================>
>
> > Info source: 10.10.10.10 (?), elected via Auto-RP
>
> > Uptime: 00:00:54, expires: 00:02:02
> > R2#
> >
> > R2#sh ip pim rp map
>
> > PIM Group-to-RP Mappings
> >
> > Group(s) 224.11.11.11/32
> > RP 10.10.10.10
> >
>
> > Without any pings from R2 to this group there is maping ...Auto RP
> sent
> > the update via maping agent R0 to R2
> >
> >
> >
>
> ----- Original Message -----
> From: Roy Waterman
> To: Mohamed El Henawy
> Cc: Mark Matters ; Keegan.Holley_at_sungard.com ; G2 ; Cisco
> certification ; nobody_at_groupstudy.com
> Sent: Thursday, August 27, 2009 12:50 AM
> Subject: Re: Auto RP with sparse-mode and no dm-fallback..and its
> working
>
>
> Hi Mohammed
>
> Looks like RP = mapping agent = 10.
>
> *Mar 1 00:36:16.159: Auto-RP(0): Received RP-discovery, from
> 10.10.10.10, <-- received from mapping agent
> RP_cnt 1, ht 181
>
> Have you configured both ip pim send rp announce & send rp discovery
> on 10.10.10.10?
> You should expect to see the mappings on your routers as they start
> automatically listening to 224.0.1.40 as soon as u configured pim...
>
> As Keegan mentioned, please post the configs...
>
> Regards
> Roy
>
>
> 2009/8/26 Mohamed El Henawy <m.henawy_at_link.net>
>
> What i dont understand is how come we are enabling only sparse and
> yet we can
> see the maping on all the routers...why use BSR then
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> ----------------------------------------------------------------------
>
>
>
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> 08/26/09 12:16:00
>
>
>
>
> --
> Regards
> Roy
>
>
>
> --------------------------------------------------------------------------
>
>
>
> No virus found in this incoming message.
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> 08/26/09 12:16:00
>
>
>
>
> --
> Regards
> Roy
>
>
>
> -----------------------------------------------------------------------------
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>
>
>
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Received on Sat Aug 29 2009 - 09:21:32 ART