multicast problem

Unanswered Question
Feb 14th, 2007


We encountered one problem with multicast behavior after software upgrade on our Cat3750.

Our used network topology is shown below:









H_1 ? is multicast Receiver;

H_2 ? is multicast Receiver;

H_3 ? is multicast Sender and Receiver;

R1 ? is Cisco7606;

R2 ? is Cat_3750 with IOS  c3750-advipservicesk9-mz.122-35.SE1;

RP ? is another router which perform Rendezvous point function;

Problem description:

H_3 is multicast sender and receiver which sending and requesting the same multicast group.

Then if receiver H_1 or H_2 request this multicast group they will have to wait certain period of time (more then 2min) while they will get this traffic.

They will receive multicast traffic only when R flag in (S, G) entry on router R1 will change from R to T.

If one of the receivers (H_1) is already receiving multicast traffic for this group and other receiver H_2 will request this group again it will receive multicast traffic immediately without any delay.

We encountered this problem also with IOS versions:

12.2(25) SEC2


12.2(25) FZ

There is no this problem with 12.2(25)SEC1 (but this version has security holes and we don?t want to use it).

Is it possible to know in which IOS release it will be or it is fixed?


I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
bellocarico Wed, 02/14/2007 - 08:55

Also, can you post the relevant multicast config for the 3 routers?

kanaru Mon, 02/19/2007 - 22:29

We are using pim-sparse mode on all our routers and static mapping for RP.


This Discussion