Re: Q. ip multicast helper: -> Broadcast -> Mcast -> Broadcast

From: Pierre-Alex GUANEL (paguanel@hotmail.com)
Date: Sun Oct 08 2006 - 10:07:36 ART


ERRATA:

I meant :

"I have labbed it and the answer is NO! It cannot be on the EGRESS "
interface.

----- Original Message -----
From: "Pierre-Alex GUANEL" <paguanel@hotmail.com>
To: <sabri_esame@yahoo.com>; ">" <rukelly@cisco.com>; ">"
<shha77@gmail.com>; <dan.bliss@gmail.com>
Sent: Sunday, October 08, 2006 3:05 PM
Subject: Re: Q. ip multicast helper: -> Broadcast -> Mcast -> Broadcast

> Dear Sabrina,
>
>
>
> First of all congratulations on your achievement.
>
> This is to your honour that you kept at it after a defeat. Especially when
> you knew you were ready.
>
> I wonder what made the different this time. Would you mind sharing with
us?
>
>
>
> Now on a technical note, you may be interested in the answer to the
question
> you posted on September 21st:
>
> "Could you really get it (multicast helper-map) working with the
helper-map
> on the egress
> > interface on the last hop router?"
>
> I have labbed it and the answer is NO! It cannot be on the ingress
> interface.
>
> In addition you DO need the "ip directed broadcast" on the last hop
router,
> otherwise it does not work.
>
> -- so the router will not accept or generate directed broadcast if this
> statement is not there, to reply to a previous mail on internal router
> mechanisms. --
>
> (NB. If you search the archive you will find a mail from me a looong time
> ago, saying it is possible. In fact I had made a configuration
mistake.All
> the routers were in the same VLAN, so of course no problem to pass the
> multicast traffic (hey, hey !!! )
>
> Here is the proof of concep showing that it does not work with the
multicast
> helper on the egress interfacet:
>
> (You can check my mail on 10/8/2006 in response to group study member
> "Multicast docs 12.2 cd wrong?" to see
> the config when it works)
>
> Best regards
>
> Pierre-Alex
>
>
>
> Diagram
> ----------
>
>
> -Server>>-broadcast-stream-
> (1)-R2--(2)---multicast----(3) -R3---(4)----receiver===R4
>
>
> Configs:
> ---------
>
> !r2
>
> interface FastEthernet0/0
> ip address 172.16.2.1 255.255.255.0
> ip pim sparse-mode
> ip multicast helper-map broadcast 225.1.1.1 100
> duplex auto
> speed auto
> end
>
> r2#sh access-list 100
> Extended IP access list 100
> 10 permit udp any any eq 65300
>
>
> !r3
>
> interface Ethernet0/0
> ip address 192.168.108.203 255.255.255.0
> ip directed-broadcast
> ip multicast helper-map 225.1.1.1 192.168.108.255 100
> ip ospf priority 255
> half-duplex
> end
>
>
> interface Serial0/3
> bandwidth 128
> ip address 10.2.3.3 255.255.255.0
> ip pim sparse-mode
> load-interval 30
> clock rate 128000
>
> interface Loopback0
> ip address 150.1.3.3 255.255.255.255
> ip pim sparse-mode
> ip igmp join-group 225.1.1.1
>
> access-list 100 permit udp any any eq 65300
>
>
> !r4
>
> interface Ethernet0/0
> ip address dhcp
> ip access-group 100 in
> half-duplex
>
> r4#sh access-list 100
> Extended IP access list 100
> 10 permit udp any any eq 65300
> 20 permit ip any any
>
> !sw1
>
> sw1#sh vlan br
>
> VLAN Name Status Ports
> ---- -------------------------------- --------- --------------------------

--
> ---
>
> 20   VLAN0020                         active    Fa0/2, Fa0/23
> 30   VLAN0030                         active    Fa0/3, Fa0/4
>
>
> sw1#sh cdp nei
> Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
>                   S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone
>
> Device ID            Local Intrfce         Holdtme   Capability
Platform
> Port ID
> r2                  Fas 0/2               167            R S      2620
> Fas 0/0
> r4                  Fas 0/4               162            R S      2611
> Eth 0/0
> R3                Fas 0/3               162            R S      2611
> Eth 0/0
>
> Server is on port fa 0/23
>
> Verification:
> --------------
>
> R3 is receiving the multicast stream- (loopback 0 joined the group
> 225.1.1.1) : Packets received: 64728
>
> ****************************************
> R3#sh ip mroute 225.1.1.1 count
> IP Multicast Statistics
> 4 routes using 2496 bytes of memory
> 3 groups, 0.33 average sources per group
> Forwarding Counts: Pkt Count/Pkts per second/Avg Pkt Size/Kilobits per
> second
> Other counts: Total/RPF failed/Other drops(OIF-null, rate-limit etc)
>
> Group: 225.1.1.1, Source count: 1, Packets forwarded: 64728, Packets
> received: 64728
>   RP-tree: Forwarding: 64728/100/33/26, Other: 64728/0/0
>   Source: 172.16.2.200/32, Forwarding: 0/0/0/0, Other: 0/0/0
> ****************************************
>
>
> But no converstion to broadcast is accomplished (because there is no
match)
>
> ****************************************
>
> R3#sh access-list 100
> Extended IP access list 100
>     10 permit udp any any eq 65300
> ****************************************
>
>
> R4 is not receiving  any udp traffic from broadcast :
>
> ****************************************
> r4#sh access-list 100
> Extended IP access list 100
>     10 permit udp any any eq 65300
>     20 permit ip any any
> ****************************************
>
>
>
>
>
>
>
>
>
>
>
>
>
> >
> > ----- Original Message -----
> > From: "sabrina pittarel" <sabri_esame@yahoo.com>
> > To: "Russell Kelly (rukelly)" <rukelly@cisco.com>; "shha"
> <shha77@gmail.com>
> > Cc: <ccielab@groupstudy.com>
> > Sent: Thursday, September 21, 2006 5:23 AM
> > Subject: Re: Q. ip multicast helper: Mcast -> Broadcast -> Mcast
> >
> >
> > > Hi Russell,
> > >  thanks for the reply...
> > > Could you really get it working with the helper-map on the egress
> > interface on the last hop router?
> > >  I believe Cisco Documentation is not accurate in that. In a
> > Brodcast->Multicast->Broadcast "regular" senario, the mroute helper
> address
> > should be configured on the *ingress* interface of both the first and
the
> > last hop router.
> > >
> > >  Also, note that the first hop router (that in the example shown by
the
> > documentation is the router performing the Broadcast to multicast
> > conversion) has PIM enabled on the interface receiving the broadcast
> > traffic.
> > >   interface ethernet 0
> > >
> > >     ip directed-broadcast
> > >
> > >     ip multicast helper-map broadcast 224.5.5.5 120
> > >
> > >     ip pim dense-mode
> > >
> > >
> > > Sabrina
> > >
> > >
> > >
> > >
> > > ----- Original Message ----
> > > From: Russell Kelly (rukelly) <rukelly@cisco.com>
> > > To: sabrina pittarel <sabri_esame@yahoo.com>; shha <shha77@gmail.com>
> > > Cc: ccielab@groupstudy.com
> > > Sent: Wednesday, September 20, 2006 1:33:16 AM
> > > Subject: RE: Q. ip multicast helper: Mcast -> Broadcast -> Mcast
> > >
> > > Normally this command is used the other way around :-) i.e. to forward
> > > broadcasts across a MC network.  This enables you to set the
helper-map
> > > on the first and last hop R3 int 1 and R2 int 4 (not int 3).  Have you
> > > tried setting the helper-map on R2 interface 4 only, as I think you
will
> > > need pim enabled on r2 int 3 if you have the helper-map on there.  As
> > > for directed broadcast - I think this is needed on outbound router
> > > interfaces only - but the univercd eg has it on both....
> > >
> > > Try this to see if it works  (I tried testing from a router interface
> > > with IP 129.1.17.1) - then you won't need pim enabled on R2 int 3 (I
> > > tried it and it sort of worked - but ran outta time to test)  I think
> > > you may need the Ip broadcast-address command on R3 int 1
> > >
> > > R3 interface 1:
> > > -----------------
> > >
> > > ip forward-protocol udp 31337
> > >
> > > interface Serial1/2
> > > ip address 129.1.13.3  255.255.255.0
> > > ip pim dense-mode
> > > ip multicast helper-map 225.25.25.25 192.10.1.255 100
> > > encapsulation ppp
> > >
> > > access-list 100 permit udp  129.1.17.0 0.0.0.255 host 225.25.25.25 eq
> > > 31337
> > >
> > > R3 interface 2:
> > > -----------------
> > >
> > > interface Serial1/3
> > > ip address  129.1.23.3 255.255.255.0
> > > ip directed-broadcast
> > > encapsulation ppp
> > >
> > >
> > > R2 interface 3:
> > > -----------------
> > >
> > > ip forward-protocol udp 31337
> > >
> > > interface Serial1/1
> > > ip address 129.1.23.2 255.255.255.0
> > > Enc ppp
> > >
> > > R2 interface  4:
> > >   -----------------
> > >
> > > interface Ethernet0/0
> > > description "to SW1 e0/2"
> > > ip address 192.10.1.2 255.255.255.0
> > > ip directed-broadcast
> > > ip multicast helper-map broadcast 225.25.25.25 100
> > > encapsulation ppp
> > > ip pim dense-mode
> > > ip igmp join-group 225.25.25.25
> > >
> > > access-list 100 permit udp 129.1.17.0 0.0.0.255  any eq 31337
> > >
> > >
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> > > sabrina pittarel
> > > Sent: 17 September 2006 18:07
> > > To: shha
> > > Cc: ccielab@groupstudy.com
> > > Subject: Re: Q. ip multicast helper: Mcast -> Broadcast -> Mcast
> > >
> > > Thank you for the help...I'll try.
> > >  But "ip directed-broadcast" is usually used to allow directed
broadcast
> > > traffic to be forworded out of that interface as regular broacast. It
> > > should not affect ingress traffic on the interface (routers always
> > > accept ingress broadcast AFAIK).
> > >  Anyway, IOS works is  misterious ways, you never know :-)
> > >
> > >  Sabrina
> > >
> > > ----- Original Message ----
> > > From: shha <shha77@gmail.com>
> > > To: sabrina pittarel <sabri_esame@yahoo.com>
> > > Cc: ccielab@groupstudy.com
> > > Sent: Sunday, September 17, 2006 8:08:26 AM
> > > Subject: Re: Q. ip multicast helper: Mcast -> Broadcast -> Mcast
> > >
> > > Can you add ip directed-broadcast on R2 interface 3.Normally router
> > > block broadcast traffic.
> > >
> > >
> > >
> > >  On 9/16/06, sabrina pittarel <sabri_esame@yahoo.com> wrote: Hi, I'm
> > > trying to use the multicast helper feature to convert from multicast
to
> > > directed broadcast and into multicast again.
> > > Topology
> > >
> > > Mcast                transport netw
> > > Source ---------- R3 ---- .....------ R2 ------- Receiver
> > > 225.25.25.25    1   2               3    4
> > >
> > > On R3 interface 1 I convert  225.25.25.25 into directed broadcast for
R2
> > > interface 3 subnet (ex 129.1.23.255) I have no problem getting this
> > > directed brodcast traffic to R2 interface 3.
> > > On R2 interface 3 I convert  broadcast back into 225.25.25.25.
> > > On R2 interface 4 I'm statically joining the 225.25.25.25 group (for
> > > testing purposes).
> > > PIM Dense mode is enabled on R3 interface 1, R2 interface 4
> > >
> > > I cannot make this working if I don't enable pim on R2 interface 3 as
> > > well.
> > > But if I do so, R2 complains because it is receiving multicast traffic
> > > on an interface where there are no PIM neighbors and the received
> > > traffic is not sourced from the connected network:
> > >
> > > *Sep 16 22:16:52.039: %MROUTE-3-NO_PIM_NBR: There is no PIM neighbor
on
> > > this IDB: Serial1/1 -Process= "PIM Process", ipl= 0, pid= 132
> > >
> > > Has anyone been able to make this working without PIM on R2 interface
> 3?
> > >
> > >
> > > The configureation is the following:
> > >
> > > R3 interface 1:
> > > -----------------
> > >
> > > ip forward-protocol udp 31337
> > >
> > > interface Serial1/2
> > > ip address 129.1.13.3  255.255.255.0
> > > ip pim dense-mode
> > > ip multicast helper-map 225.25.25.25 129.1.23.255 100 encapsulation
ppp
> > > serial restart-delay 0
> > >
> > > access-list 100 permit udp  129.1.17.0 0.0.0.255 host 225.25.25.25 eq
> > > 31337
> > >
> > > R3 interface 2:
> > > -----------------
> > >
> > > interface Serial1/3
> > > ip address  129.1.23.3 255.255.255.0
> > > ip directed-broadcast
> > > encapsulation ppp
> > >
> > >
> > > R2 interface 3:
> > > -----------------
> > >
> > > ip forward-protocol udp 31337
> > >
> > > interface Serial1/1
> > > ip address 129.1.23.2 255.255.255.0
> > > ip pim dense-mode              <<<<< without it it doesn't work...
> > >  ip multicast helper-map broadcast 225.25.25.25 100 encapsulation ppp
> > >
> > > access-list 100 permit udp 129.1.17.0 0.0.0.255  any eq 31337
> > >
> > > R2 interface 4:
> > >   -----------------
> > >
> > > interface Ethernet0/0
> > > description "to SW1 e0/2"
> > > ip address 192.10.1.2 255.255.255.0
> > > ip pim dense-mode
> > > ip igmp join-group 225.25.25.25
> > >
> > >
> > > **************************************************
> > > On R2 Without the "pim" cmd on R3 interface 3:
> > > **************************************************
> > >
> > > "deb ip packet" and "deb ip mpacket" output:
> > >
> > > *Sep 17 01:13:28.622: IP: s=129.1.17.7 (Serial1/1), d=255.255.255.255,
> > > len 44, rcvd 2
> > > *Sep 17 01:13:28.622:     UDP src=49182, dst=31337
> > >
> > > sh ip mroute
> > > IP Multicast Routing Table
> > > Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C -
> > > Connected,
> > >        L - Local, P - Pruned, R - RP-bit  set, F - Register flag,
> > >        T - SPT-bit set, J - Join SPT, M - MSDP created entry,
> > >        X - Proxy Join Timer Running, A - Candidate for MSDP
> > > Advertisement,
> > >        U - URD, I - Received Source Specific Host Report,
> > >        Z - Multicast Tunnel, z - MDT-data group sender,
> > >        Y - Joined MDT-data group, y - Sending to MDT-data group
> > > Outgoing interface flags: H - Hardware switched, A - Assert winner
> > > Timers: Uptime/Expires
> > > Interface state: Interface, Next-Hop or VCD, State/Mode
> > >
> > > (*, 225.25.25.25), 00:00:03/00:02:56, RP 0.0.0.0, flags: DCL
> > >   Incoming interface: Null, RPF nbr 0.0.0.0
> > >   Outgoing interface list:
> > >     Ethernet0/0, Forward/Dense, 00:00:03/00:00:00
> > >
> > > (*, 224.0.1.40), 00:00:03/00:02:56, RP 0.0.0.0, flags:  DCL
> > >   Incoming interface: Null, RPF nbr  0.0.0.0
> > >   Outgoing interface list:
> > >     Ethernet0/0, Forward/Dense, 00:00:03/00:00:00
> > >
> > >
> > > *************************************
> > > On R2 WITH the ip pim dense command
> > > *************************************
> > >
> > > "deb ip packet" and "deb ip mpacket" output:
> > >
> > > *Sep 17 01:16:50.618: IP: s=129.1.17.7 (Serial1/1), d=255.255.255.255,
> > > len 44, rcvd 2
> > > *Sep 17 01:16:50.618:     UDP src=53508, dst=31337
> > > *Sep 17 01:16:50.618: IP(0): s=129.1.17.7 (Serial1/1) d=225.25.25.25
> > > (Ethernet0/0) id=0, ttl=252, prot=17, len=44(44), mforward
> > >
> > >
> > > sh ip mroute
> > >
> > > IP Multicast Routing Table
> > > Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C -
> > > Connected,
> > >        L - Local, P - Pruned, R - RP-bit set, F - Register flag,
> > >        T - SPT-bit set, J - Join SPT, M -  MSDP created entry,
> > >        X - Proxy Join Timer Running, A - Candidate for MSDP
> > > Advertisement,
> > >        U - URD, I - Received Source Specific Host Report,
> > >        Z - Multicast Tunnel, z - MDT-data group sender,
> > >        Y - Joined MDT-data group, y - Sending to MDT-data group
> > > Outgoing interface flags: H - Hardware switched, A - Assert winner
> > > Timers: Uptime/Expires
> > > Interface state: Interface, Next-Hop or VCD, State/Mode
> > >
> > > (*, 225.25.25.25), 00:03:23/stopped, RP  0.0.0.0, flags: DCL
> > >   Incoming interface: Null, RPF nbr 0.0.0.0
> > >   Outgoing interface list:
> > >     Ethernet0/0, Forward/Dense, 00:03:23/00:00:00
> > >     Serial1/1, Forward/Dense, 00:01:31/00:00:00
> > >
> > > (129.1.17.7, 225.25.25.25), 00:01:33/00:02:58, flags: LT
> > >   Incoming interface:  Serial1/1, RPF nbr 0.0.0.0
> > >   Outgoing interface list:
> > >     Ethernet0/0, Forward/Dense, 00:01:33/00:00:00
> > >
> > > (*, 224.0.1.40), 00:03:23/00:02:41, RP 0.0.0.0, flags: DCL
> > >   Incoming interface: Null, RPF nbr  0.0.0.0
> > >   Outgoing interface list:
> > >     Ethernet0/0, Forward/Dense, 00:03:23/00:00:00
> > >
> > >
> > > Sabrina
> > >
> > >


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