MRouter understanding

[David Kondicz]

Hi all,

i just want to understand why we need to config mrouter in igmp config.

I have a Cisco DCM as IGMP multicast source. Output addresses are  239.129.0.1 to 239.129.0.10

The DCM is connected to Catalyst 3560X into gi 0/1

Interface gi 0/1 config is:

int mode access

int access vlan 500

I have 4 user ports from int gi 1/1 to gi 1/4

gi 1/2 and gi 1/4 are trunk ports

I have everything on default. It meas I havent set this config:  ip igmp snooping vlan 500 mrouter interface gi 0/1

And while I enter show ip igmp snooping mrouter see waht is hapen

#show ip igmp snooping mrouter

Vlan    ports

----    -----

  30    Gi1/2(dynamic), Gi1/4(dynamic)

On some trunk ports using IGMP filters are not working.

Can it be cased becouse no mrouter port/vlan is configured?

#show ip igmp snooping groups

Vlan      Group                    Type        Version     Port List

-----------------------------------------------------------------------

500        239.129.0.1                igmp        v2          Gi1/1, Gi1/2, Gi1/3

                                                           Gi1/4

500        239.129.0.2                igmp        v2          Gi1/1, Gi1/2, Gi1/3

                                                           Gi1/4

500        239.129.0.3                igmp        v2          Gi1/1, Gi1/2, Gi1/3

                                                           Gi1/4

500        239.129.0.4                igmp        v2          Gi1/1, Gi1/2, Gi1/3

                                                           Gi1/4

500        239.129.0.5                igmp        v2          Gi1/1, Gi1/2, Gi1/3

                                                           Gi1/4

500        239.129.0.6                igmp        v2          Gi1/1, Gi1/2, Gi1/3

                                                           Gi1/4

500        239.129.0.7                igmp        v2          Gi1/1, Gi1/2, Gi1/3

                                                           Gi1/4

most intersting thing is that on int gi 1/1-1/3 is igmp filter permit 239.129.0.1 239.129.0.7

but on gi 1/4 is another filter permin 239.129.0.1 239.129.0.6

Thanx a lot guys for any idea!

BR

Dave

[David Kondicz]

And my last question for this if are there any chanse to remove dynamicly added Mrouters ports.

Becouse as i see switch automaticly add all trunk interfaces as mouter interface.

Thank you

BR

dave

[Aleksandr Serov]

Hi
In many cases you have no need to configure mrouter staticaly. Mrouter port is a port which is receiving PIM hello or join packets and used for forwarding all multicast packets.

Please look who is an IGMP qurier in your vlan. If there is no any qurier you can just disable snooping or configure a qurier.

Hope it helps

Aleksandr

[David Kondicz]

Thank you Alexandr,

in thic case the queuer is CISCO DCM and on all switches i need to set up as ququer dcm`s address

Thank zou

dave