RE: Sparse Mode basic Question

From: Gupta, Gopal (NWCC) (gopal.gupta@hp.com)
Date: Sun Nov 11 2007 - 14:29:25 ART


Hi Tarun,
Thanks for your reply.
R5 is the RP and MA and R5 is the hub having 3 Spokes R1, R3, R4 .. when
i configure on R5 PIM NBMA Mode, it still sends the Traffic for a
particular group out the three spokes where only R3 has requested the
traffic.
Here is the config,
 
R5
 
interface Serial1/0
 ip address 155.1.0.5 255.255.255.0
 ip pim nbma-mode
 ip pim sparse-mode
 encapsulation frame-relay
 no ip route-cache cef
 no ip route-cache
 serial restart-delay 0
 no dce-terminal-timing-enable
 frame-relay map ip 155.1.0.1 501 broadcast frame-relay map ip
155.1.0.3 503 broadcast frame-relay map ip 155.1.0.4 504 broadcast
end
 
Ip pim autorp listener
Ip pim send-rp-announce int lo 0 scope 16 int 15
Ip pim send-rp-discovery int lo0 svope 16

R5#sh ip mr 232.2.2.2

IP Multicast Routing Table

(*, 232.2.2.2 ), 00:18:05/00:03:14, RP 150.1.5.5 , flags: S
 Incoming interface: Null, RPF nbr 0.0.0.0
 Outgoing interface list:
   Serial1/0, 155.1.0.3 , Forward/Sparse, 00:17:43/00:03:14
 
R5#ping 232.2.2.2

Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 232.2.2.2 , timeout is 2 seconds:

Reply to request 0 from 155.1.67.6 , 324 ms Reply to request 0 from
155.1.67.6 , 728 ms Reply to request 0 from 155.1.67.6 , 504 ms

        Debugs:-
        
        *Mar 1 11:26:16.277: Serial1/0(o): dlci 504(0x7C81), pkt type
0x800(IP), datagramsize 444
        *Mar 1 11:26:16.277: Serial1/0(o): dlci501(0x7C51), pkt type
0x800(IP), datagramsize 444
        *Mar 1 11:26:16.289:Serial1/0(o): dlci 503(0x7C71), pkt type
0x800(IP), datagramsize 444
        
        These packets are packets for 232.2.2.2 address Sorced from R5
itself
R3
interface Serial1/0.1 point-to-point
 ip address 155.1.0.3 255.255.255.0
 ip pim sparse-mode
 encapsulation frame-relay
 no ip route-cache cef
 no ip route-cache
 serial restart-delay 0
 no dce-terminal-timing-enable
Frame-relay interface-dlci 305

Ip pim autorp listener

Same on R4 and R1

On spoke sides I have subinterfaces attached to R5 only. And configured
for Sparse mode and no extra config other than this.
If you need further logs and information, kindly ask me, I will provide
with that.

Regards,
Gops
 
________________________________

        
 <http://www.hp.com/>

        Gopal Gupta
Network Competency Engineer
Hewlett-Packard

+44 17 93819715 Phone
gopal.gupta@hp.com
http://www.hp.com <http://www.hp.com/>
________________________________

        
 

________________________________

From: Tarun Pahuja [mailto:pahujat@gmail.com]
Sent: Sunday, November 11, 2007 21:21
To: Gupta, Gopal (NWCC)
Cc: Cisco certification; Alex Steer
Subject: Re: Sparse Mode basic Question

Gops,
           My answer refers to your general question.unfortunately, Your
config pasted in one of the threads is partial which makes it difficult
for me to comment on it. Make sure that you are running nbma-mode on
all physical interfaces connected to the FR cloud in your case. Also,
since nbma-mode is supported under spare-mode , where are your Mapping
agents located?
 
In Sparse mode only the initial stream goes through the router which is
the RP, once the sender and receiver realize that they have started
communication, the multicast tree transitions from shared tree to source
tree and the traffic from the source to the receiver chooses the
shortest path between the two. The transition from Shared tree to source
tree is configurable, by default it is one packet from the source to the
receiver.
 
HTH,
Tarun

On Nov 11, 2007 6:52 AM, Gupta, Gopal (NWCC) <gopal.gupta@hp.com> wrote:

         Hi GS,
        
        I have one very basic question that is throttling my mind..
        Does traffic move to RP first to reach the hosts or traffic can
move
        natively.
        Practically it is moving natively
        
        Say R3-->R2-->R1 and R1 is the Rp and R2 needs to send traffic
to
        R3...will it go natively or go throgh R2--R1--R2--R3.
        
        Regards,
        Gops
        
        -----Original Message-----
        From: Alex Steer [mailto:alex.steer@eison.co.uk]
        Sent: Sunday, November 11, 2007 16:36
        To: Gupta, Gopal (NWCC)
        Cc: Cisco certification
        Subject: RE: PIM NBMA Mode
        
        Nope I don't
        
        And prune overrides still apply to sparse mode
        
        -----Original Message-----
        From: Gupta, Gopal (NWCC) [mailto:gopal.gupta@hp.com]
        Sent: 11 November 2007 10:56
        To: Alex Steer
        Cc: Cisco certification
        Subject: RE: PIM NBMA Mode
        
        
        Hi Alex,
        You mean to say that it will still send traffic to all DLCis
despite
        others didn't ask for the traffic??
        As far as I know Pim Nbma works only for Sparse mode which does
not send
        traffic to all DLCIs if others didn't ask for it. And it
forwards
        traffic based on the ip add and not Interface when nbma mode
configured.
        
        prunning is meant for Dense mode only which forwards the traffic
first
        and then prune...which doesn't understand IP PIM NBMA mode
command and
        the issue of pruning will come in picture with the Dense mode.
        
        Thanks
        Gops
        
        
        -----Original Message-----
        From: Alex Steer [mailto: alex.steer@eison.co.uk]
        Sent: Sunday, November 11, 2007 15:52
        To: Gupta, Gopal (NWCC)
        Cc: Cisco certification
        Subject: RE: PIM NBMA Mode
        
        Hi Gops,
        
        It might be, it might not. Could you send a full copy of your
show ip
        mroute on all of the routers please (specifically the S,G
entry)?
        
        Nbma is primarily to stop a prune from one of the spokes sent to
r5 from
        pruning the other neighbors (default behaviour without nbma
mode). The
        other neighbors don't see the prune due to the Non-broadcast
nature of
        the interface and so don't prune override it. Pim nbma causes
pim to
        store network-hop information for that interface, that doesn't
mean it
        can unicast the packet to that 1 neighbor though, merely means
it wont
        prune the interface when it receives a prune from one of the
neighbors.
        It would be good for my own study to see the output.
        
        -----Original Message-----
        From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On
Behalf Of
        Gupta, Gopal (NWCC)
        Sent: 11 November 2007 09:56
        To: Cisco certification
        Subject: PIM NBMA Mode
        
        Hi Folks,
        
        There is issue with pim NBMA mode.
        
        R5 is the hub Router and sending traffic to group 232.2.2.2
<http://232.2.2.2/> , The problem
        here is that despite of putting ip pim NBMA command on R5 Serial

        interface, i am getting three replies; means R5 is still sending
traffic
        to all DLCIs configured under R5 serial interface.
        
        R5#ping 232.2.2.2 <http://232.2.2.2/>
        
        Type escape sequence to abort.
        Sending 1, 100-byte ICMP Echos to 232.2.2.2 <http://232.2.2.2/>
, timeout is 2 seconds:
        
        Reply to request 0 from 155.1.67.6 <http://155.1.67.6/> , 324 ms
Reply to request 0 from
        155.1.67.6 <http://155.1.67.6/> , 728 ms Reply to request 0 from
155.1.67.6 <http://155.1.67.6/> , 504 ms
        
        Debugs:-
        
        *Mar 1 11:26:16.277: Serial1/0(o): dlci 504(0x7C81), pkt type
        0x800(IP), datagramsize 444 *Mar 1 11:26:16.277: Serial1/0(o):
dlci
        501(0x7C51), pkt type 0x800(IP), datagramsize 444 *Mar 1
11:26:16.289:
        Serial1/0(o): dlci 503(0x7C71), pkt type 0x800(IP), datagramsize
444
        
        These packets are packets for 232.2.2.2 <http://232.2.2.2/>
address.
        
        R5#sh ip mr 232.2.2.2 <http://232.2.2.2/>
        
        IP Multicast Routing Table
        
        (*, 232.2.2.2 <http://232.2.2.2/> ), 00:18:05/00:03:14, RP
150.1.5.5 <http://150.1.5.5/> , flags: S
         Incoming interface: Null, RPF nbr 0.0.0.0 <http://0.0.0.0/>
         Outgoing interface list:
           Serial1/0, 155.1.0.3 <http://155.1.0.3/> , Forward/Sparse,
00:17:43/00:03:14
        
        
        Config :--
        
        interface Serial1/0
         ip address 155.1.0.5 <http://155.1.0.5/> 255.255.255.0
<http://255.255.255.0/>
         ip pim nbma-mode
         ip pim sparse-mode
         encapsulation frame-relay
         no ip route-cache cef
         no ip route-cache
         serial restart-delay 0
         no dce-terminal-timing-enable
         frame-relay map ip 155.1.0.1 <http://155.1.0.1/> 501 broadcast
frame-relay map ip
        155.1.0.3 <http://155.1.0.3/> 503 broadcast frame-relay map ip
155.1.0.4 <http://155.1.0.4/> 504 broadcast end
        
        Any Comments...how to overcome this, may i be i am missing
something
        here.
        
        Thanks
        Gops
        
        



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