Ok,
Basic question is this.
show ip igmp snooping groups
Is not returning the multicast groups I am creating
More in-depth explanation.
I want to test multicast. I am on a flat network, and I just want to be able to multicast between clients on the same vlan, and even the same switch. I can use a multicast tool to mimic both a sending and receiving host. This tool works as expected on network A(where I know multicast works), while on network B I get a couple different results.
If multicasting between 2 hosts on the same Vlan and the same switch:
Then I can transmit and receive, however, show ip igmp snooping groups is does not populate with the multicast group I am using.
Now I am not routing between vlans, and I am on the same switch /vlan.
here is the IGMP vlan config
show ip igmp snooping vlan 888
Global IGMP Snooping configuration:
-------------------------------------------
IGMP snooping : Enabled
IGMPv3 snooping (minimal) : Enabled
Report suppression : Enabled
TCN solicit query : Disabled
TCN flood query count : 2
Robustness variable : 2
Last member query count : 2
Last member query interval : 1000
Vlan 888:
--------
IGMP snooping : Enabled
CAPWAP enabled : Disabled
IGMPv2 immediate leave : Disabled
Multicast router learning mode : pim-dvmrp
CGMP interoperability mode : IGMP_ONLY
Robustness variable : 2
Last member query count : 2
Last member query interval : 1000
My test multicast does seem to be transmitting/receiving correctly
Sending
Singlewire Software Packet 254 239.0.1.2:20480 TTL: 16
Singlewire Software Packet 255 239.0.1.2:20480 TTL: 16
Singlewire Software Packet 256 239.0.1.2:20480 TTL: 16
Singlewire Software Packet 257 239.0.1.2:20480 TTL: 16
Singlewire Software Packet 258 239.0.1.2:20480 TTL: 16
Singlewire Software Packet 259 239.0.1.2:20480 TTL: 16
Receiving
Receive Singlewire Software Packet 254 : 239.0.1.2:20480 : Receive Total 26
Receive Singlewire Software Packet 255 : 239.0.1.2:20480 : Receive Total 27
Receive Singlewire Software Packet 256 : 239.0.1.2:20480 : Receive Total 28
Receive Singlewire Software Packet 257 : 239.0.1.2:20480 : Receive Total 29
Receive Singlewire Software Packet 258 : 239.0.1.2:20480 : Receive Total 30
Receive Singlewire Software Packet 259 : 239.0.1.2:20480 : Receive Total 31
show ip igmp snooping groups
Seems to return these two unrelated multicast groups which are on a different vlan.
Switch#show ip igmp snooping groups
Vlan Group Type Version Port List
-----------------------------------------------------------------------
889 224.0.5.128 igmp v2 Fa0/33, Gi0/2
889 239.255.255.250 igmp v2 Fa0/13, Gi0/2
Do I have to setup PIM/RP/etc on a layer 3 switch/router? How do you get a ip igmp snooping groups to populate on a layer 2 switch?
Best Answer
for the vlan you need to enable the multicast on it , it must configured to be interface vlan and under this interface configure * ip pim sparse-dense-mode*
something like
interface Vlan1
ip address 1.1.1.1 255.255.255.0
ip pim sparse-dense-mode
end
i found a very useful documentation that is talking about your problem exactly in this link Multicast Does Not Work in the Same VLAN in Catalyst Switches