From: Matt Mullen (mullenm@gmail.com)
Date: Fri Sep 16 2005 - 10:25:40 GMT-3
Hi Godswill,
I also would prefer going with the text when sitting the lab even though
the routers seem to contradict it. Since there is a wealth of information as
you have shown stating the expected behavior I think the chances are good
that the "correct" solution would be to either make the interface
sparse-dense mode or enable autorp listener.
Matt
On 9/16/05, Godswill Oletu <oletu@inbox.lv> wrote:
>
> Matt,
>
> This is also my understanding, I even went back to re-read my Cisco press
> books...Page 244 of CCIE Practical Studies Vol. 2 by Karl Solie & Leah
> Lynch states that and I quote...
>
> "Auto-RP uses 224.0.1.39 <http://224.0.1.39> and
224.0.1.40<http://224.0.1.40>multicast groups to send
> information. Auto-RP floods this information through PIM dense mode. For
> auto-RP to work properly, the routers must use the "ip pim
> sparse-dense-mode" interface command. WITHOUT the dense mode capability,
> the
> RP will never be learned."
>
> Cisco documentation seems to be backing that up:
>
>
http://www.cisco.com/en/US/products/ps6350/products_configuration_guide_chapt
er09186a008049ccb3.html#wp1112026
>
> The relevant section states that:
> Prerequisites for Using Auto-RP
> .When configuring Auto-RP, you must either specify sparse mode using the
> ip
> pim sparse-mode command and configure the Auto-RP listener feature using
> the
> ip pim autorp listener command (Steps 6 and 7) or specify sparse-dense
> mode
> (Step 8) using the ip pim sparse-dense mode command.
>
> I will prefer to stay with the text, especially in the exam, despite the
> fact that it has been proven to work in sparse-mode with configuring the
> ip
> pim autorp listerner.
>
>
> Dave,
>
> The 'ip pim sparse-mode' is specially useful on two occations:
> 1. It makes multicast traffic eg video streams from tying down the strick
> priority broadcast queue reserve for management control multicast traffics
> like ospf, eigrp, etc. Without the command, huge multicast video streams
> can
> burden down this queue thus starving it. It essentially make these
> multicast
> traffics to be "normal" queued at the interface just like other normal
> traffics.
>
> 2. On multipoint interfaces, properly processing join and prune messages
> is
> made difficult, because one router on that multi-interface prune's message
> can cut off traffic for every other router connected via that mutipoint
> interface, the "ip pim sparse-mode" will allow for the proper processing
> of
> these messages.
>
> HTH
> Godswill Oletu
>
>
>
> ----- Original Message -----
> From: "Matt Mullen" <mullenm@gmail.com>
> To: "Schulz, Dave" <DSchulz@dpsciences.com>
> Cc: <ccielab@groupstudy.com>
> Sent: Thursday, September 15, 2005 9:00 PM
> Subject: Re: Multicast issue: Auto-RP over Sparse-Dense mode
>
>
> > My understanding was that if you had an interface running in sparse
> mode,
> > it
> > wouldn't listen to the AutoRP advertisements. This was based on various
> > sources including the IPExpert audio bootcamp and this statement in the
> > DocCD that seems to imply that is the case:
> > **
> > *Note *If router interfaces are configured in sparse mode, Auto-RP can
> > still
> > be used if all routers are configured with a static RP address for the
> > Auto-RP groups.
> > I thought that getting around not being able to use AutoRP on sparse
> mode
> > interfaces was the whole point of the 'ip pim autorp listener' command
> > being
> > introduced. Here's the DocCD description of that command:
> > ip pim autorp listener
> > To cause IP multicast traffic for the two Auto-RP groups
> > 224.0.1.39 <http://224.0.1.39><http://224.0.1.39>and
> > 224.0.1.40 <http://224.0.1.40> <http://224.0.1.40> to be Protocol
> Independent Multicast (PIM)
> > dense mode flooded across interfaces operating in PIM sparse mode, use
> the
> > ip pim autorp listener command in global configuration mode. To disable
> > this
> > feature, use the no form of this command.
> > Anyway, it does look as if maybe that was the behavior at some point but
> > when I labbed this up I get the same results as you. So Cisco must have
> > changed IOS to allow AutoRP advertisements to be processed by sparse
> mode
> > interfaces by default. I'm only running a 12.2 mainline image, so it
> must
> > have been this way for a while and I never noticed. Since this seems to
> be
> > the case, I would like to ask the group is there any situation where the
> > 'ip
> > pim autorp listener' would still be applicable?
> > Thanks,
> > Matt
> > On 9/15/05, Schulz, Dave <DSchulz@dpsciences.com> wrote:
> >>
> >> Interesting thought. I would like to hear more discussion on this (or
> >> get
> >> more information on your thought of sparse-dense mode). Andrew noticed
> >> that
> >> the loopback from R4 was in the IGP routing. I corrected that and
> >> everything
> >> is workingalong with leaving it ip pim sparse mode. I was thinking
> that
> >> the ip pim nbma was taking care of the dense mode and so, I deleted
> that
> >> (trying to break) it. However, it kept on working. Hmmmthen the
> question
> >> is.why bother using ip pim nbma. What kind of question in the lab
> would
> >> prevent us from using it or not using it?
> >>
> >> Dave Schulz,
> >>
> >> Email: dschulz@dpsciences.com <dschulz@dpsciences.com%20>
> >>
> >> ------------------------------
> >>
> >> *From:* Matt Mullen [mailto:mullenm@gmail.com]
> >> *Sent:* Thursday, September 15, 2005 4:52 PM
> >> *To:* Schulz, Dave
> >> *Cc:* ccielab@groupstudy.com
> >> *Subject:* Re: Multicast issue: Auto-RP over Sparse-Dense mode
> >>
> >> Hi Dave,
> >>
> >> By default an interface in Sparse mode will not listen to AutoRP
> >> advertisements because AutoRP uses dense mode for operation. To get
> >> around
> >> this you can configure sparse-dense mode on the interface, or you can
> >> override the behavior on a sparse-mode configured interface so that it
> >> does
> >> listen to AutoRP advertisements with the 'ip pim autorp listener'
> >> command.
> >> Interface s0.1 on R2 is configured for Sparse-mode, so it will not
> listen
> >> to the Auto-RP advertisements being sent from R4 for the group
> >> 224.4.4.0 <http://224.4.4.0><http://224.4.4.0/>.
> >> If you configure interface s0.1 on R2 as sparse-dense or use the above
> >> mentioned command on the interface, you should start to see the AutoRP
> >> advertisements being forwarded across the rest of your topology.
> >>
> >> HTH,
> >>
> >> Matt
> >>
> >> On 9/15/05, *Schulz, Dave* <DSchulz@dpsciences.com> wrote:
> >>
> >> Here is the situation.... I am doing multicast with Auto-RP over
> >> Sparse-Dense (configs below). R2 has a DLCI to R3 and R4 (multipoint
> >> subif), and, also a point-to-point subinterface on a separate dlci to
> >> R5.
> >>
> >> R2 is announcing itself as the RP for groups 224.2.2.0<http://224.2.2.0>
> >> <http://224.2.2.0/>
> >> R4 is announcing itself as the RP for groups 224.4.4.0<http://224.4.4.0>
> >> <http://224.4.4.0/>
> >>
> >> I believe the configurations are correct. However, when I do the show
> >> ip pim rp map, I get the following:
> >>
> >> R2#sh ip pim rp map
> >> PIM Group-to-RP Mappings
> >> This system is an RP (Auto-RP)
> >> This system is an RP-mapping agent (Serial0.2)
> >>
> >> Group(s) 224.2.2.0/24 <http://224.2.2.0/24> <http://224.2.2.0/24>
> >> RP 20.20.20.1 <http://20.20.20.1> <http://20.20.20.1/> (?), v2v1
> >> Info source: 20.20.20.1 <http://20.20.20.1> <http://20.20.20.1/>(?),
> via Auto-RP
> >> Uptime: 23:19:40, expires: 00:02:15
> >>
> >> R3#sh ip pim rp map
> >> PIM Group-to-RP Mappings
> >>
> >> Group(s) 224.2.2.0/24 <http://224.2.2.0/24> <http://224.2.2.0/24>
> >> RP 20.20.20.1 <http://20.20.20.1> <http://20.20.20.1/> (?), v2v1
> >> Info source: 172.16.1.2 <http://172.16.1.2> <http://172.16.1.2/> (?),
> via Auto-RP
> >> Uptime: 23:18:23, expires: 00:02:39
> >> R3#
> >>
> >> R4# sh ip pim rp map
> >> PIM Group-to-RP Mappings
> >> This system is an RP (Auto-RP)
> >>
> >> Group(s) 224.2.2.0/24 <http://224.2.2.0/24> <http://224.2.2.0/24>
> >> RP 20.20.20.1 <http://20.20.20.1> <http://20.20.20.1/> (?), v2v1
> >> Info source: 172.16.1.2 <http://172.16.1.2> <http://172.16.1.2/> (?),
> via Auto-RP
> >> Uptime: 00:00:05, expires: 00:02:50
> >> Group(s) 224.4.4.0/24 <http://224.4.4.0/24> <http://224.4.4.0/24>
> >> RP 40.40.40.1 <http://40.40.40.1> <http://40.40.40.1/> (?), v2v1
> >> Info source: 40.40.40.1 <http://40.40.40.1> <http://40.40.40.1/> (?),
> via Auto-RP
> >> Uptime: 23:06:44, expires: 00:01:17
> >>
> >>
> >> R5#sh ip pim rp map
> >> PIM Group-to-RP Mappings
> >>
> >> Group(s) 224.2.2.0/24 <http://224.2.2.0/24> <http://224.2.2.0/24>
> >> RP 20.20.20.1 <http://20.20.20.1> <http://20.20.20.1/> (?), v2v1
> >> Info source: 172.16.1.2 <http://172.16.1.2> <http://172.16.1.2/> (?),
> via Auto-RP
> >> Uptime: 23:05:19, expires: 00:02:50
> >>
> >> Problem: for some reason, I cannot get the 224.4.40 group to be mapped
> >> throughout the network. I run the same scenario under BSR and it works
> >> fine. Also, running the MRM utility shows no errors. Thoughts? Here
> >> are the configs......
> >>
> >>
> >> hostname R2
> >> ip multicast-routing
> >> !
> >> interface Loopback0
> >> ip address 20.20.20.1 <http://20.20.20.1>
> >> <http://20.20.20.1/>255.255.255.0 <http://255.255.255.0><
> http://255.255.255.0/>
> >> ip pim sparse-dense-mode
> >> !
> >> interface Serial0
> >> no ip address
> >> encapsulation frame-relay
> >> no frame-relay inverse-arp
> >> frame-relay lmi-type cisco
> >> !
> >> interface Serial0.1 multipoint
> >> ip address 192.168.1.2 <http://192.168.1.2> <http://192.168.1.2/>
> >> 255.255.255.0 <http://255.255.255.0><http://255.255.255.0/>
> >> ip pim nbma-mode
> >> ip pim sparse-mode
> >> frame-relay map ip 192.168.1.2 <http://192.168.1.2> <
> http://192.168.1.2/> 203
> >> frame-relay map ip 192.168.1.3 <http://192.168.1.3> <
> http://192.168.1.3/> 203 broadcast
> >> frame-relay map ip 192.168.1.4 <http://192.168.1.4> <
> http://192.168.1.4/> 204 broadcast
> >> no frame-relay inverse-arp
> >> !
> >> interface Serial0.2 point-to-point
> >> ip address 172.16.1.2 <http://172.16.1.2> <http://172.16.1.2/>
> >> 255.255.255.0 <http://255.255.255.0><http://255.255.255.0/>
> >> ip pim sparse-dense-mode
> >> ip igmp join-group 224.4.4.4 <http://224.4.4.4> <http://224.4.4.4/>
> >> frame-relay interface-dlci 205
> >> !
> >> router eigrp 1
> >> network 172.16.0.0 <http://172.16.0.0> <http://172.16.0.0/>
> >> network 192.168.1.0 <http://192.168.1.0> <http://192.168.1.0/>
> >> no auto-summary
> >> no eigrp log-neighbor-changes
> >> !
> >> ip pim send-rp-announce Loopback0 scope 16 group-list 1
> >> ip pim send-rp-discovery Serial0.2 scope 16
> >> !
> >> ip mrm manager TST
> >> manager Loopback0 group 224.4.4.4 <http://224.4.4.4> <http://224.4.4.4/
> >
> >> senders 8
> >> receivers 9 sender-list 8
> >> !
> >> access-list 1 permit 224.2.2.0 <http://224.2.2.0> <http://224.2.2.0/>
> >> 0.0.0.255 <http://0.0.0.255><http://0.0.0.255/>
> >> access-list 8 permit 50.50.50.1 <http://50.50.50.1> <http://50.50.50.1/
> >
> >> access-list 9 permit 40.40.40.1 <http://40.40.40.1> <http://40.40.40.1/
> >
> >> !
> >>
> >> R3
> >> hostname R3
> >> ip multicast-routing
> >> !
> >> interface Loopback0
> >> ip address 30.30.30.1 <http://30.30.30.1> <http://30.30.30.1/>
> >> 255.255.255.0 <http://255.255.255.0><http://255.255.255.0/>
> >> ip pim sparse-dense-mode
> >> !
> >> interface Serial0
> >> ip address 192.168.1.3 <http://192.168.1.3> <http://192.168.1.3/>
> >> 255.255.255.0 <http://255.255.255.0><http://255.255.255.0/>
> >> ip pim sparse-dense-mode
> >> encapsulation frame-relay
> >> frame-relay map ip 192.168.1.2 <http://192.168.1.2> <
> http://192.168.1.2/> 302 broadcast
> >> frame-relay map ip 192.168.1.3 <http://192.168.1.3> <
> http://192.168.1.3/> 302
> >> frame-relay map ip 192.168.1.4 <http://192.168.1.4> <
> http://192.168.1.4/> 302 broadcast
> >> no frame-relay inverse-arp
> >> frame-relay lmi-type cisco
> >> !
> >> router eigrp 1
> >> network 192.168.1.0 <http://192.168.1.0> <http://192.168.1.0/>
> >> no auto-summary
> >> no eigrp log-neighbor-changes
> >> !
> >>
> >> R4
> >>
> >> hostname R4
> >> ip multicast-routing
> >> !
> >> interface Loopback0
> >> ip address 40.40.40.1 <http://40.40.40.1> <http://40.40.40.1/>
> >> 255.255.255.0 <http://255.255.255.0><http://255.255.255.0/>
> >> ip pim sparse-dense-mode
> >> ip mrm test-receiver
> >> !
> >> interface Serial0
> >> ip address 192.168.1.4 <http://192.168.1.4> <http://192.168.1.4/>
> >> 255.255.255.0 <http://255.255.255.0><http://255.255.255.0/>
> >> ip pim sparse-dense-mode
> >> encapsulation frame-relay
> >> frame-relay map ip 192.168.1.2 <http://192.168.1.2> <
> http://192.168.1.2/> 402 broadcast
> >> frame-relay map ip 192.168.1.3 <http://192.168.1.3> <
> http://192.168.1.3/> 402 broadcast
> >> frame-relay map ip 192.168.1.4 <http://192.168.1.4> <
> http://192.168.1.4/> 402
> >> no frame-relay inverse-arp
> >> frame-relay lmi-type cisco
> >> !
> >> router eigrp 1
> >> network 192.168.1.0 <http://192.168.1.0> <http://192.168.1.0/>
> >> no auto-summary
> >> no eigrp log-neighbor-changes
> >> !
> >> ip pim send-rp-announce Loopback0 scope 16 group-list 1
> >> !
> >> access-list 1 permit 224.4.4.0 <http://224.4.4.0>
> >> <http://224.4.4.0/>0.0.0.255 <http://0.0.0.255><http://0.0.0.255/>
> >> !
> >>
> >>
> >> R5
> >> hostname R5
> >> ip multicast-routing
> >> !
> >> interface Loopback0
> >> ip address 50.50.50.1 <http://50.50.50.1> <http://50.50.50.1/>
> 255.255.255.0 <http://255.255.255.0>
> >> <http://255.255.255.0/>
> >> ip pim sparse-dense-mode
> >> ip mrm test-sender
> >> !
> >> interface Serial0
> >> ip address 172.16.1.5 <http://172.16.1.5> <http://172.16.1.5/>
> >> 255.255.255.0 <http://255.255.255.0><http://255.255.255.0/>
> >> ip pim sparse-dense-mode
> >> encapsulation frame-relay
> >> frame-relay interface-dlci 502
> >> frame-relay lmi-type cisco
> >> !
> >> router eigrp 1
> >> network 172.16.0.0 <http://172.16.0.0> <http://172.16.0.0/>
> >> no auto-summary
> >> no eigrp log-neighbor-changes
> >> !
> >> end
> >>
> >> Dave Schulz
> >> Email: dschulz@dpsciences.com <mailto:dschulz@dpsciences.com >
> >>
> >> _______________________________________________________________________
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> >
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