From: Brian Hescock (bhescock@xxxxxxxxx)
Date: Fri Feb 02 2001 - 14:40:26 GMT-3
I would suggest everyone read "Developing IP Multicast Networks", by Beau
Williamson, pages 445-471 (NBMA). The isbn number is 1-57870-077-9.
NBMA mode is only applicable with sparse mode when running multipoint
(which in this situation is the case) and only really affects anything if
a prune is sent. Here's why:
R1----R2
|
R3
R1 is the hub and R2 and R3 are spokes. There's a receiver on R2 and R3
and R1 has interface S0 in the outbound interface list. Now let's say R2
leaves the group (which won't happen if you have "ip igmp join-group"). A
prune would be sent from R2 to R1. R3 won't hear the prune request so he
will never send an override to say he still needs the traffic. R1 will
prune the interface and both R2 and R3 will stop getting traffic.
Putting ip pim nbma on S0 on R1 creates two separate entries in the
outbound interface list for S0, one for R2 and one for R3 (if there are
receivers on both). A prune from one of those router will result in only
their respective entry being removed from the outbound interface and won't
affect the other router.
That's all ip pim nbma mode does, in a nutshell. It *shouldn't* matter if
you aren't doing ip pim nbma mode if you have static joins on all of your
routers, no prunes will be sent and traffic will keep flowing.
Brian
On Fri, 2 Feb 2001, Alejandro Cadarso wrote:
> Hi,
>
> IP pim-nbma mode enabled on an interface, enables pim to be communicated
> via unicasts - for non-native multicast media. It would need to be
> configured on all pim routers in a frame cloud, then if you configure on
> R1 and R3:
>
> interface Serial0
> ip pim nbma-mode
> it must work.
>
> zhuqingliu wrote:
>
> > Allyn,
> >
> > Yes, The hub router has been configured with sparse-mode and nbma-mode on t
he frame relay interface. Here are the configurations for these routers.
> > /////////////////////////////////
> > !!!!! R3
> > ip multicast-routing
> > ip dvmrp route-limit 7000
> > !
> > interface Serial0
> > ip address 137.20.100.35 255.255.255.224
> > ip pim sparse-mode
> > encapsulation frame-relay
> > ip ospf network broadcast
> > ip ospf priority 0
> > frame-relay map ip 137.20.100.33 305 broadcast
> > frame-relay map ip 137.20.100.34 305 broadcast
> > !
> > ip pim rp-address 137.20.64.5
> >
> > /////////////////////////////////
> > !!!!! R2
> > ip multicast-routing
> > ip dvmrp route-limit 7000
> > !
> > interface Ethernet0
> > ip address 137.20.64.5 255.255.240.0
> > ip accounting output-packets
> > ip pim sparse-mode
> > interface Serial0
> > no ip address
> > encapsulation frame-relay
> > clockrate 64000
> > frame-relay lmi-type ansi
> > !
> > interface Serial0.1 multipoint
> > ip address 137.20.100.34 255.255.255.224
> > ip pim nbma-mode
> > ip pim sparse-mode
> > ip ospf network broadcast
> > ip ospf priority 100
> > frame-relay map ip 137.20.100.33 501 broadcast
> > frame-relay map ip 137.20.100.35 503 broadcast
> >
> > //////////
> > !!! r1
> > ip multicast-routing
> > ip dvmrp route-limit 7000
> > !
> > interface Ethernet0
> > ip address 137.20.20.1 255.255.255.0
> > ip pim sparse-mode
> > ip igmp join-group 224.1.1.1
> > !
> > interface Serial0
> > ip address 137.20.100.33 255.255.255.224
> > ip pim sparse-mode
> > encapsulation frame-relay
> > ip ospf network broadcast
> > ip ospf priority 0
> > no fair-queue
> > clockrate 64000
> > frame-relay map ip 137.20.100.34 105 broadcast
> > frame-relay map ip 137.20.100.35 105 broadcast
> > !
> > ip pim rp-address 137.20.64.5
> >
> > ////////////////////////
> > The rp address is the ethernet address of r2.
> >
> > Thanks.
> >
> > Perry
> >
> > ----- Original Message -----
> > From: Allyn Baskerville <abaskerville@ibeam.com>
> > To: 'zhuqingliu' <zql@liming.com>
> > Sent: Thursday, February 01, 2001 1:06 AM
> > Subject: RE: IP multicast over framerelay
> >
> >
> >> You have to use sparse-mode PIM in conjunction with the pim nbma-mode on t
he
> >> frame interface. Have you done this? Allyn
> >>
> >> -----Original Message-----
> >> From: zhuqingliu [mailto:zql@liming.com]
> >> Sent: Wednesday, January 31, 2001 3:14 AM
> >> To: ccielab@groupstudy.com
> >> Subject: IP multicast over framerelay
> >>
> >>
> >> Hi, All,
> >>
> >> The following chart is the work arround.
> >>
> >> Join 224.1.1.1 RP
> >> r1---------------/--r2---------------r4
> >> F.R. /
> >> /
> >> /
> >> r3
> >> PIM sparse-mode
> >>
> >> r1 , r2 and r3 are connected with frame-relay and r2 is the hub. no
> >> sub-interface is used for r2.
> >> r1 join group 224.1.1.1
> >> r2 is the RP and pim nbma-mode configured for r2's frame-relay interface
.
> >>
> >> The problem is that r3 can only ping 224.1.1.1 once in a while.
> >> //////////////////////////////////////////////////////////////////////////
//
> >> ////////////////////////////
> >> r3#ping 224.1.1.1
> >>
> >> Type escape sequence to abort.
> >> Sending 1, 100-byte ICMP Echos to 224.1.1.1, timeout is 2 seconds:
> >>
> >> Reply to request 0 from 137.20.100.33, 156 ms
> >> r3#ping 224.1.1.1
> >>
> >> Type escape sequence to abort.
> >> Sending 1, 100-byte ICMP Echos to 224.1.1.1, timeout is 2 seconds:
> >> .
> >> r3#ping 224.1.1.1
> >>
> >> Type escape sequence to abort.
> >> Sending 1, 100-byte ICMP Echos to 224.1.1.1, timeout is 2 seconds:
> >> .
> >> r3#
> >> //////////////////////////////////////////////////////////////////////////
//
> >> ////////////////////////////
> >>
> >> Thanks in advance.
> >>
> >> Perry
> >>
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:28:34 GMT-3