From: Ravi (s_ravichandran@xxxxxxxxxxx)
Date: Sun Jan 13 2002 - 11:27:37 GMT-3
Hi,
The following scenario is a copy and paste from archive (Oct or Nov 2001). I
did most of the multicast scenarios discussed in this list and Jeff Doyle
vol II, and understand quite well. This is the hardest one as it works some
times and it does not work some times. I would appreciate if someone could
help me to find solution for this. I tried the solutions given by BriBrian
Hescock but did not work.
Regards,
Ravi
----------------------------
Three routers R2, R1 and R4. All interconnected using FR. R1 is in the
centre and will have to route Multicast between its serial interface to R2
and R4. R2 and R4 have a tokenring interfaces at which SD-mode is
configured. The same is for all the serial interfaces.
LAN--------R2-------------FR---------------R1----------FR---------------R4--
LAN
IP MULTICAST-ROUTING IP
MULTICAST-ROUTING IP
MULTICAST-ROUTING
PIM-S-D
PIM-S-D PIM-S-D
igmp-join 224.1.1.1
224.1.1.1 announced by RP
igmp-join 224.2.2.2
R2 is RP and mapping agent ONLY for 224.1.1.1. So
basicly 224.1.1.1 is
using Sparse-mode and 224.2.2.2 is using Dense !
PIM Sparse Dense is configured on all Frame-relay
interfaces and the
tokenring interfaces.
On the tokenring interface of R2 are the two igmp
joins configured.
R1 and R4 are showing the RP (sh ip pim rp mapping)
R1 can ping 224.1.1.1 and 224.2.2.2
R4 can only ping 224.2.2.2
======================================================
----- Original Message -----
From: "Albert Lu" <albert_ccie@yahoo.com>
To: "'Ravi'" <s_ravichandran@hotmail.com>
Cc: <ccielab@groupstudy.com>; <bhescock@cisco.com>
Sent: Sunday, January 13, 2002 6:07 AM
Subject: RE: Subject: multicast tip and Multicast Sparse-Dense
> It looks abit confusing, if you could explain the problem in your own
words
> that would be great. Having a quick look, I think it's trying to do
Auto-RP
> using only pim sparse-mode. You need sparse-dense mode. If that is
correct,
> I will explain why.
>
> Albert
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> Ravi
> Sent: Sunday, January 13, 2002 3:42 PM
> To: ccielab@groupstudy.com; bhescock@cisco.com
> Subject: Subject: multicast tip and Multicast Sparse-Dense
>
>
> Hi,
>
> I am doing some multicast labs, finding it very hard to understand. I need
> some help please....
>
> I took a example discussed here a month ago (attached below)
>
> I get the same result as what Sijbren Beukenkamp experienced. After
spending
> hours and hours on the lab and Cisco site, could not get it working. I
would
> like to bring this topic back and get some solution to this problem.
>
> Regards,
> Ravi
>
>
>
> Consider the following.
> > >
> > > Three routers R2, R1 and R4. All interconnected
> > using FR. R1 is in the
> > > centre and will have to route Multicast between
> > its serial interface to
> > R2
> > > and R4. R2 and R4 have a tokenring interfaces at
> > which SD-mode is
> > > configured. The same is for all the serial
> > interfaces.
> > >
> > >
> >
>
LAN--------R2-------------FR---------------R1----------FR---------------R4--
> -
> -----LAN
> > >
> > > IP MULTICAST-ROUTING IP
> > MULTICAST-ROUTING IP
> > MULTICAST-ROUTING
> > > PIM-S-D
> > PIM-S-D PIM-S-D
> > > igmp-join 224.1.1.1
> > > 224.1.1.1 announced by RP
> > > igmp-join 224.2.2.2
> > >
> > > R2 is RP and mapping agent ONLY for 224.1.1.1. So
> > basicly 224.1.1.1 is
> > > using Sparse-mode and 224.2.2.2 is using Dense !
> > > PIM Sparse Dense is configured on all Frame-relay
> > interfaces and the
> > > tokenring interfaces.
> > > On the tokenring interface of R2 are the two igmp
> > joins configured.
> > >
> > > R1 and R4 are showing the RP (sh ip pim rp
> > mapping)
> > > R1 can ping 224.1.1.1 and 224.2.2.2
> > > R4 can only ping 224.2.2.2
> > >
> > >
> > > What's wrong with this picture !
>
> ==========================================================
>
>
> >>The previous discussion about multicast made me think about a problem I
> > >>see occasionally and I thought I'd pass it along. Don't use anything
in
> > >>the 224.0.0.x range for a multicast address. It will work fine if
the
> > >>source and destination are in the same vlan (unless you're using one
of
> > >>the reserved addresses, such as 224.0.0.10 for eigrp, which would
> > >>probably wouldn't be a good thing to do... ;-). The reason it doesn't
> > >>work when routing multicast is the 224.0.0.x is a "link-local"
address,
> > >>it never gets forwarded off the local segment, you will never get ip
> > >>multicast for 224.0.0.x to work across a router unless you bridged it
> > >>(haven't tried it but it should work).
> > >>
> > >>Most people wouldn't use 224.0.0.x but I see it happen occasionally
and
> > >>wanted to help save some people the grief of troubleshooting the
problem
> > >>if you used that range of addresses by mistake. Another common
problem
> > >>in production networks is many multicast servers have a default ttl of
1
> > >>and, since one of the first things a router does is decrement the ttl
by
> > >>one, the packets get dropped at the router. The solution is to
increase
> > >>the ttl of the multicast server to be at least one higher than the
> > >>number of hops to the furtherest multicast receiver.
> > >>
> > >>Brian
> ============================================================
> Brian Hescock <bhescock@cisco.com>
> > Sent by: nobody@groupstudy.com
> > 31-10-2001 14:26
> > Please respond to Brian Hescock
> >
> >
> > To: Sijbren
> > Beukenkamp/Netherlands/IBM@IBMNL
> > cc: ccielab@groupstudy.com
> > Subject: Re: Multicast Sparse-Dense
> > Mode
> >
> >
> >
> > Pinging from R1 means the packets will be
> > process-switched. When pinging
> > from R4 the packets on R1
> > will be fast-switched. Configure "no ip
> > mroute-cache" on the outgoing
> > interface on R1 and then see
> > if you can ping from R4. If not, put an ip igmp
> > join-group on the
> > outgoing interface on R1 and see
> > if you can ping from R4 and get a response from R1.
> >
> > There have been several multicast fast-switching
> > bugs where sometimes you
> > don't even get an
> > interface in the OIL when you have a join-group
> > command on that interface.
> > As a workaround, what
> > will often work is removing join-group and remove
> > pim, let pim timeout
> > then put the commands back
> > on. If that doesn't work, do the same thing again
> > but once the commands
> > are off the interface do a
> > "shut", wait a few seconds, do a "no shut" and put
> > the commands back on
> > the interface. You should
> > then see the outbound interface in the OIL. This
> > isn't something you
> > should have to do, just a
> > workaround due to a multicast fast-switching bug.
> >
> > Brian
> >
> > Sijbren Beukenkamp wrote:
> >
> > > Consider the following.
> > >
> > > Three routers R2, R1 and R4. All interconnected
> > using FR. R1 is in the
> > > centre and will have to route Multicast between
> > its serial interface to
> > R2
> > > and R4. R2 and R4 have a tokenring interfaces at
> > which SD-mode is
> > > configured. The same is for all the serial
> > interfaces.
> > >
> > >
> >
>
LAN--------R2-------------FR---------------R1----------FR---------------R4--
> -
> -----LAN
> > >
> > > IP MULTICAST-ROUTING IP
> > MULTICAST-ROUTING IP
> > MULTICAST-ROUTING
> > > PIM-S-D
> > PIM-S-D PIM-S-D
> > > igmp-join 224.1.1.1
> > > 224.1.1.1 announced by RP
> > > igmp-join 224.2.2.2
> > >
> > > R2 is RP and mapping agent ONLY for 224.1.1.1. So
> > basicly 224.1.1.1 is
> > > using Sparse-mode and 224.2.2.2 is using Dense !
> > > PIM Sparse Dense is configured on all Frame-relay
> > interfaces and the
> > > tokenring interfaces.
> > > On the tokenring interface of R2 are the two igmp
> > joins configured.
> > >
> > > R1 and R4 are showing the RP (sh ip pim rp
> > mapping)
> > > R1 can ping 224.1.1.1 and 224.2.2.2
> > > R4 can only ping 224.2.2.2
> > >
> > >
> > > What's wrong with this picture !
> > >
> > > Met vriendelijke groet/ Kind regards,
> > > Sijbren
> > >
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++
> > > Ing. Sijbren Beukenkamp IBM Global Services
> > > Internetworking Specialist Integrated
> > Technology Services
> > >
> > Networking & Connectivity
> > > Services
> > >
> > http://www.ibm.com/services/nc/
> > > GSM +31 (0)6 53761703 The Netherlands
> > > Office: +31 (0)30 2850 666
> >
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:56:26 GMT-3