Cat3550 igmp support

[umetsu]

Does Cat3550 support "ip igmp snooping querier" ?

I checked it out the command on Cat3550,but,I couldn't find any command related to this at all.

IOS(EMI):12.1(13)EA1a

Please let me know asap.

[umetsu]

I'm thinking about the following network.

multicast sender------L2SW---L3 Cat3550

multicast receiver------+

Multicast traffic streams to the all ports on the L2SW.There's no igmp querier from Cat3550.

In this situation,is it possible to send a multicast traffic to the multicast receiver only ?

[umetsu]

I configured like below.

interface fastethernet0/17

no switchport

ip address 172.16.1.254 255.255.255.0

ip igmp join-group 224.1.2.3

no cdp enable

!

But,"v2 membership query" did NOT streame at all.

After I added the "ip pim dense-mode" command,"v2 membership query" streamed.

Why ?

Do I have to define both "ip igmp join-group" and "ip pim dense-mode" in this situation ?

Please let me know asap.

[Kevin Dorrell]

It may be more to do with what is connected on F0/17. Is it a switch? And does it do IGMP snooping? If so, it needs to know that it is talking to a multicast router so that it can potentially open all streams on that port. It does so either by static configuration on the switch, or by detecting the presence of the router by PIM hellos.

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat2950/12120ea2/2950cr/cli1.htm#wp3395441

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat2950/12120ea2/2950cr/cli1.htm#wp1365537

Kevin Dorrell

Luxembourg

Kevin Dorrell

Luxembourg

[umetsu]

>It may be more to do with what is connected on >F0/17. Is it a switch?

Yes.L2SW is connected.

I configured "ip igmp snooping vlan 1 interface fa0/12" on L2SW.

fa0/12 is a connection between Cat3550 and L2SW.

But,igmp v2 membership query does NOT appear after applying "ip pim dense-mode" in Cat3550.

Why ? I think that multicast sender and receiver are on the same subnet,therefore, I don't need to use multicast routing protocol.

Why ?

[locp]

Umetsu,

For multicast to functional ( on cisco stuffs ), you DO need to defined ip multicast-routing AND ip pim XXX-mode where XXX can be DM or SM mode.

HTH,

lP.

[jkilleda]

Hello MASARU ,

3550 is a layer 3 switch , IGMP querier along with IGMP/CGMP snooping is used to constrain multicast traffic, it will be doing IGMP snooping by default, and this should ensure that the multicast only goes to the ports where it is wanted.